Technology | Meta Intelligence Systems

Technology

Databases, the middleware in front of them, and the systems underneath. Written from primary documentation, with configuration you can actually run rather than illustrative fragments.

Areas

Five areas, each with reference pages and guides.

Databases

Relational, document, vector, graph, time-series, and streaming engines - how each stores data and what that costs you.

Open Middleware

The layer between the application and the database: connection pooling, load balancing, and failover.

Open Open Source

Linux, Kubernetes, and the cloud-native stack that most production infrastructure runs on.

Open Systems

Operating systems, CPU and GPU architecture, networking, containers, and observability.

Open Technology map

Every technology covered here and how it connects - dependencies, alternatives, and what is deployed together.

Open Architecture

Design patterns for distributed systems and data platforms.

Open

How it connects

Databases, middleware, systems and infrastructure - excluding AI, which has its own map at /ai - by what depends on, replaces, or pairs with what.

Choose a starting point, then follow a recorded connection.

Use the map to decide what to read next: compare alternatives, look into a listed dependency or find a complementary tool. Lanes group entries by category and sort them alphabetically, so position does not signal importance or a reading order.

These are editorial recorded associations, not live topology or universal dependencies. Each arrow runs from the entry that records a relationship to the entry it names. It does not show traffic, execution order or a verified deployment.

Dependency
Recorded use
Alternatives
Complements

This view shows 39 technologies joined by 163 directed records.

How to read this map

Every arrow points from the entry that owns a record to the entry it references. Reciprocal records stay separate, and the line pattern identifies the field, not strength or certainty. The linked guides give the context; a record on its own does not explain technical necessity.

Dependency (dependsOn): A lists B in dependsOn; check the guide for scope and configuration.
Recorded use (usedBy): A lists B in usedBy. This is not converted into a dependency claim about B.
Alternatives (alternatives): A lists B as an alternative to compare, not a guaranteed drop-in replacement.
Complements (complements): A lists B as a complement, not a requirement to deploy both.

A filled dot leads to a guide or concept explanation; a hollow dot leads to a relationship profile. The number on a card counts its direct records in this view. Selecting a card highlights only those direct records, not a transitive dependency tree.

Technologies appear when they have at least 1 outgoing record before filtering and belong to Database, Data Engineering, Middleware, Infrastructure, Systems, Observability. Connections to entries outside this view are not drawn, so absence here does not mean that no relationship exists.

Text view: every displayed node and recorded connection

Each sentence names the record owner first, then the referenced entry. A connection appears under both endpoints for lookup, without reversing its meaning. This view and its links work without JavaScript.

Data Engineering

Apache Airflow Data Engineering

Open guide: Apache Airflow

7 direct recorded connections in this view.

Dependency / dependsOnApache Airflow lists Linux as a dependency.
Complements / complementsApache Airflow lists Apache Kafka as a complement.
Complements / complementsApache Airflow lists PostgreSQL as a complement.
Complements / complementsApache Airflow lists Apache Spark as a complement.
Complements / complementsApache Kafka lists Apache Airflow as a complement.
Complements / complementsApache Spark lists Apache Airflow as a complement.
Recorded use / usedByLinux records Apache Airflow in its usedBy list. This is a recorded use association, not an inferred dependency.

Apache Iceberg Data Engineering

Open guide: Apache Iceberg

3 direct recorded connections in this view.

Complements / complementsApache Iceberg lists Snowflake as a complement.
Complements / complementsApache Iceberg lists Apache Spark as a complement.
Complements / complementsApache Spark lists Apache Iceberg as a complement.

Apache Kafka Data Engineering

Open guide: Apache Kafka

9 direct recorded connections in this view.

Complements / complementsApache Airflow lists Apache Kafka as a complement.
Dependency / dependsOnApache Kafka lists Linux as a dependency.
Recorded use / usedByApache Kafka records Debezium in its usedBy list. This is a recorded use association, not an inferred dependency.
Recorded use / usedByApache Kafka records Confluent Schema Registry in its usedBy list. This is a recorded use association, not an inferred dependency.
Complements / complementsApache Kafka lists Apache Airflow as a complement.
Complements / complementsApache Spark lists Apache Kafka as a complement.
Dependency / dependsOnConfluent Schema Registry lists Apache Kafka as a dependency.
Dependency / dependsOnDebezium lists Apache Kafka as a dependency.
Recorded use / usedByLinux records Apache Kafka in its usedBy list. This is a recorded use association, not an inferred dependency.

Apache Spark Data Engineering

Open guide: Apache Spark

7 direct recorded connections in this view.

Complements / complementsApache Airflow lists Apache Spark as a complement.
Complements / complementsApache Iceberg lists Apache Spark as a complement.
Dependency / dependsOnApache Spark lists Linux as a dependency.
Complements / complementsApache Spark lists Apache Kafka as a complement.
Complements / complementsApache Spark lists Apache Iceberg as a complement.
Complements / complementsApache Spark lists Apache Airflow as a complement.
Recorded use / usedByLinux records Apache Spark in its usedBy list. This is a recorded use association, not an inferred dependency.

Confluent Schema Registry Data Engineering

Open guide: Confluent Schema Registry

2 direct recorded connections in this view.

Recorded use / usedByApache Kafka records Confluent Schema Registry in its usedBy list. This is a recorded use association, not an inferred dependency.
Dependency / dependsOnConfluent Schema Registry lists Apache Kafka as a dependency.

Debezium Data Engineering

Open guide: Debezium

6 direct recorded connections in this view.

Recorded use / usedByApache Kafka records Debezium in its usedBy list. This is a recorded use association, not an inferred dependency.
Dependency / dependsOnDebezium lists Apache Kafka as a dependency.
Dependency / dependsOnDebezium lists PostgreSQL as a dependency.
Dependency / dependsOnDebezium lists MySQL as a dependency.
Recorded use / usedByMySQL records Debezium in its usedBy list. This is a recorded use association, not an inferred dependency.
Recorded use / usedByPostgreSQL records Debezium in its usedBy list. This is a recorded use association, not an inferred dependency.

dbt Data Engineering

Open guide: dbt

4 direct recorded connections in this view.

Complements / complementsdbt lists Snowflake as a complement.
Complements / complementsdbt lists PostgreSQL as a complement.
Complements / complementsPostgreSQL lists dbt as a complement.
Complements / complementsSnowflake lists dbt as a complement.

Database

CouchDB Database

Open guide: CouchDB

3 direct recorded connections in this view.

Dependency / dependsOnCouchDB lists Linux as a dependency.
Alternatives / alternativesCouchDB lists MongoDB as an alternative.
Recorded use / usedByLinux records CouchDB in its usedBy list. This is a recorded use association, not an inferred dependency.

DynamoDB Database

Open guide: DynamoDB

1 direct recorded connection in this view. 1 further record touches an entry outside this view.

Alternatives / alternativesDynamoDB lists MongoDB as an alternative.

InfluxDB Database

Open guide: InfluxDB

5 direct recorded connections in this view.

Dependency / dependsOnInfluxDB lists Linux as a dependency.
Alternatives / alternativesInfluxDB lists TimescaleDB as an alternative.
Complements / complementsInfluxDB lists Prometheus as a complement.
Recorded use / usedByLinux records InfluxDB in its usedBy list. This is a recorded use association, not an inferred dependency.
Alternatives / alternativesTimescaleDB lists InfluxDB as an alternative.

MariaDB Database

Open guide: MariaDB

17 direct recorded connections in this view.

Dependency / dependsOnGalera Cluster lists MariaDB as a dependency.
Complements / complementsGalera Cluster lists MariaDB as a complement.
Recorded use / usedByLinux records MariaDB in its usedBy list. This is a recorded use association, not an inferred dependency.
Dependency / dependsOnMariaDB lists Linux as a dependency.
Recorded use / usedByMariaDB records Galera Cluster in its usedBy list. This is a recorded use association, not an inferred dependency.
Recorded use / usedByMariaDB records ProxySQL in its usedBy list. This is a recorded use association, not an inferred dependency.
Alternatives / alternativesMariaDB lists PostgreSQL as an alternative.
Alternatives / alternativesMariaDB lists MySQL as an alternative.
Alternatives / alternativesMariaDB lists SQL Server as an alternative.
Complements / complementsMariaDB lists Galera Cluster as a complement.
Complements / complementsMariaDB lists ProxySQL as a complement.
Complements / complementsMariaDB lists keepalived as a complement.
Alternatives / alternativesMySQL lists MariaDB as an alternative.
Alternatives / alternativesPostgreSQL lists MariaDB as an alternative.
Dependency / dependsOnProxySQL lists MariaDB as a dependency.
Complements / complementsProxySQL lists MariaDB as a complement.
Alternatives / alternativesSQL Server lists MariaDB as an alternative.

Memcached Database

Open guide: Memcached

4 direct recorded connections in this view.

Recorded use / usedByLinux records Memcached in its usedBy list. This is a recorded use association, not an inferred dependency.
Dependency / dependsOnMemcached lists Linux as a dependency.
Alternatives / alternativesMemcached lists Valkey as an alternative.
Alternatives / alternativesValkey lists Memcached as an alternative.

Milvus Database

Open guide: Milvus

9 direct recorded connections in this view.

Recorded use / usedByetcd records Milvus in its usedBy list. This is a recorded use association, not an inferred dependency.
Recorded use / usedByKubernetes records Milvus in its usedBy list. This is a recorded use association, not an inferred dependency.
Dependency / dependsOnMilvus lists Kubernetes as a dependency.
Dependency / dependsOnMilvus lists etcd as a dependency.
Alternatives / alternativesMilvus lists pgvector as an alternative.
Alternatives / alternativesMilvus lists Qdrant as an alternative.
Complements / complementsMilvus lists Kubernetes as a complement.
Complements / complementsMilvus lists etcd as a complement.
Alternatives / alternativesQdrant lists Milvus as an alternative.

MongoDB Database

Open guide: MongoDB

7 direct recorded connections in this view. 1 further record touches an entry outside this view.

Alternatives / alternativesCouchDB lists MongoDB as an alternative.
Alternatives / alternativesDynamoDB lists MongoDB as an alternative.
Recorded use / usedByLinux records MongoDB in its usedBy list. This is a recorded use association, not an inferred dependency.
Dependency / dependsOnMongoDB lists Linux as a dependency.
Alternatives / alternativesMongoDB lists PostgreSQL as an alternative.
Complements / complementsMongoDB lists Kubernetes as a complement.
Alternatives / alternativesPostgreSQL lists MongoDB as an alternative.

Database (continued)

MySQL Database

Open guide: MySQL

9 direct recorded connections in this view.

Dependency / dependsOnDebezium lists MySQL as a dependency.
Recorded use / usedByLinux records MySQL in its usedBy list. This is a recorded use association, not an inferred dependency.
Alternatives / alternativesMariaDB lists MySQL as an alternative.
Dependency / dependsOnMySQL lists Linux as a dependency.
Recorded use / usedByMySQL records Debezium in its usedBy list. This is a recorded use association, not an inferred dependency.
Alternatives / alternativesMySQL lists MariaDB as an alternative.
Alternatives / alternativesMySQL lists PostgreSQL as an alternative.
Alternatives / alternativesMySQL lists SQL Server as an alternative.
Complements / complementsMySQL lists ProxySQL as a complement.

Oracle Database Database

Open guide: Oracle Database

2 direct recorded connections in this view.

Alternatives / alternativesOracle Database lists PostgreSQL as an alternative.
Alternatives / alternativesOracle Database lists SQL Server as an alternative.

PostgreSQL Database

Open guide: PostgreSQL

37 direct recorded connections in this view. 1 further record touches an entry outside this view.

Complements / complementsApache Airflow lists PostgreSQL as a complement.
Complements / complementsdbt lists PostgreSQL as a complement.
Dependency / dependsOnDebezium lists PostgreSQL as a dependency.
Complements / complementsHAProxy lists PostgreSQL as a complement.
Complements / complementsKubernetes lists PostgreSQL as a complement.
Recorded use / usedByLinux records PostgreSQL in its usedBy list. This is a recorded use association, not an inferred dependency.
Alternatives / alternativesMariaDB lists PostgreSQL as an alternative.
Alternatives / alternativesMongoDB lists PostgreSQL as an alternative.
Alternatives / alternativesMySQL lists PostgreSQL as an alternative.
Alternatives / alternativesOracle Database lists PostgreSQL as an alternative.
Dependency / dependsOnPatroni lists PostgreSQL as a dependency.
Dependency / dependsOnPgBouncer lists PostgreSQL as a dependency.
Dependency / dependsOnPgpool-II lists PostgreSQL as a dependency.
Complements / complementsPgpool-II lists PostgreSQL as a complement.
Dependency / dependsOnpgvector lists PostgreSQL as a dependency.
Complements / complementspgvector lists PostgreSQL as a complement.
Dependency / dependsOnpg-jev lists PostgreSQL as a dependency.
Complements / complementspg-jev lists PostgreSQL as a complement.
Dependency / dependsOnPostgreSQL lists Linux as a dependency.
Recorded use / usedByPostgreSQL records PgBouncer in its usedBy list. This is a recorded use association, not an inferred dependency.
Recorded use / usedByPostgreSQL records Pgpool-II in its usedBy list. This is a recorded use association, not an inferred dependency.
Recorded use / usedByPostgreSQL records Patroni in its usedBy list. This is a recorded use association, not an inferred dependency.
Recorded use / usedByPostgreSQL records TimescaleDB in its usedBy list. This is a recorded use association, not an inferred dependency.
Recorded use / usedByPostgreSQL records pgvector in its usedBy list. This is a recorded use association, not an inferred dependency.
Recorded use / usedByPostgreSQL records pg-jev in its usedBy list. This is a recorded use association, not an inferred dependency.
Recorded use / usedByPostgreSQL records Debezium in its usedBy list. This is a recorded use association, not an inferred dependency.
Alternatives / alternativesPostgreSQL lists MariaDB as an alternative.
Alternatives / alternativesPostgreSQL lists MongoDB as an alternative.
Alternatives / alternativesPostgreSQL lists SQL Server as an alternative.
Complements / complementsPostgreSQL lists PgBouncer as a complement.
Complements / complementsPostgreSQL lists Patroni as a complement.
Complements / complementsPostgreSQL lists HAProxy as a complement.
Complements / complementsPostgreSQL lists pgvector as a complement.
Complements / complementsPostgreSQL lists pg-jev as a complement.
Complements / complementsPostgreSQL lists dbt as a complement.
Alternatives / alternativesSQL Server lists PostgreSQL as an alternative.
Dependency / dependsOnTimescaleDB lists PostgreSQL as a dependency.

Qdrant Database

Open guide: Qdrant

5 direct recorded connections in this view.

Recorded use / usedByLinux records Qdrant in its usedBy list. This is a recorded use association, not an inferred dependency.
Alternatives / alternativesMilvus lists Qdrant as an alternative.
Dependency / dependsOnQdrant lists Linux as a dependency.
Alternatives / alternativesQdrant lists pgvector as an alternative.
Alternatives / alternativesQdrant lists Milvus as an alternative.

SQL Server Database

Open guide: SQL Server

6 direct recorded connections in this view. 1 further record touches an entry outside this view.

Alternatives / alternativesMariaDB lists SQL Server as an alternative.
Alternatives / alternativesMySQL lists SQL Server as an alternative.
Alternatives / alternativesOracle Database lists SQL Server as an alternative.
Alternatives / alternativesPostgreSQL lists SQL Server as an alternative.
Alternatives / alternativesSQL Server lists PostgreSQL as an alternative.
Alternatives / alternativesSQL Server lists MariaDB as an alternative.

Snowflake Database

Open guide: Snowflake

3 direct recorded connections in this view.

Complements / complementsApache Iceberg lists Snowflake as a complement.
Complements / complementsdbt lists Snowflake as a complement.
Complements / complementsSnowflake lists dbt as a complement.

TimescaleDB Database

Open guide: TimescaleDB

5 direct recorded connections in this view.

Alternatives / alternativesInfluxDB lists TimescaleDB as an alternative.
Recorded use / usedByPostgreSQL records TimescaleDB in its usedBy list. This is a recorded use association, not an inferred dependency.
Dependency / dependsOnTimescaleDB lists PostgreSQL as a dependency.
Alternatives / alternativesTimescaleDB lists InfluxDB as an alternative.
Complements / complementsTimescaleDB lists pgvector as a complement.

Database (continued)

Valkey Database

Open guide: Valkey

4 direct recorded connections in this view.

Recorded use / usedByLinux records Valkey in its usedBy list. This is a recorded use association, not an inferred dependency.
Alternatives / alternativesMemcached lists Valkey as an alternative.
Dependency / dependsOnValkey lists Linux as a dependency.
Alternatives / alternativesValkey lists Memcached as an alternative.

pg-jev Database

Open guide: pg-jev

7 direct recorded connections in this view.

Alternatives / alternativespgvector lists pg-jev as an alternative.
Dependency / dependsOnpg-jev lists PostgreSQL as a dependency.
Alternatives / alternativespg-jev lists pgvector as an alternative.
Complements / complementspg-jev lists PostgreSQL as a complement.
Complements / complementspg-jev lists pgvector as a complement.
Recorded use / usedByPostgreSQL records pg-jev in its usedBy list. This is a recorded use association, not an inferred dependency.
Complements / complementsPostgreSQL lists pg-jev as a complement.

pgvector Database

Open guide: pgvector

10 direct recorded connections in this view. 6 further records touch entries outside this view.

Alternatives / alternativesMilvus lists pgvector as an alternative.
Dependency / dependsOnpgvector lists PostgreSQL as a dependency.
Alternatives / alternativespgvector lists pg-jev as an alternative.
Complements / complementspgvector lists PostgreSQL as a complement.
Alternatives / alternativespg-jev lists pgvector as an alternative.
Complements / complementspg-jev lists pgvector as a complement.
Recorded use / usedByPostgreSQL records pgvector in its usedBy list. This is a recorded use association, not an inferred dependency.
Complements / complementsPostgreSQL lists pgvector as a complement.
Alternatives / alternativesQdrant lists pgvector as an alternative.
Complements / complementsTimescaleDB lists pgvector as a complement.

Infrastructure

Kubernetes Infrastructure

Open guide: Kubernetes

15 direct recorded connections in this view. 5 further records touch entries outside this view.

Recorded use / usedByContainers records Kubernetes in its usedBy list. This is a recorded use association, not an inferred dependency.
Complements / complementsContainers lists Kubernetes as a complement.
Recorded use / usedByetcd records Kubernetes in its usedBy list. This is a recorded use association, not an inferred dependency.
Complements / complementsetcd lists Kubernetes as a complement.
Dependency / dependsOnKubernetes lists Linux as a dependency.
Dependency / dependsOnKubernetes lists etcd as a dependency.
Dependency / dependsOnKubernetes lists Containers as a dependency.
Recorded use / usedByKubernetes records Milvus in its usedBy list. This is a recorded use association, not an inferred dependency.
Complements / complementsKubernetes lists Prometheus as a complement.
Complements / complementsKubernetes lists PostgreSQL as a complement.
Recorded use / usedByLinux records Kubernetes in its usedBy list. This is a recorded use association, not an inferred dependency.
Dependency / dependsOnMilvus lists Kubernetes as a dependency.
Complements / complementsMilvus lists Kubernetes as a complement.
Complements / complementsMongoDB lists Kubernetes as a complement.
Complements / complementsPrometheus lists Kubernetes as a complement.

etcd Infrastructure

Open guide: etcd

12 direct recorded connections in this view. 2 further records touch entries outside this view.

Dependency / dependsOnetcd lists Linux as a dependency.
Recorded use / usedByetcd records Patroni in its usedBy list. This is a recorded use association, not an inferred dependency.
Recorded use / usedByetcd records Kubernetes in its usedBy list. This is a recorded use association, not an inferred dependency.
Recorded use / usedByetcd records Milvus in its usedBy list. This is a recorded use association, not an inferred dependency.
Complements / complementsetcd lists Patroni as a complement.
Complements / complementsetcd lists Kubernetes as a complement.
Dependency / dependsOnKubernetes lists etcd as a dependency.
Recorded use / usedByLinux records etcd in its usedBy list. This is a recorded use association, not an inferred dependency.
Dependency / dependsOnMilvus lists etcd as a dependency.
Complements / complementsMilvus lists etcd as a complement.
Dependency / dependsOnPatroni lists etcd as a dependency.
Complements / complementsPrometheus lists etcd as a complement.

Middleware

Galera Cluster Middleware

Open relationship profile: Galera Cluster

6 direct recorded connections in this view. 1 further record touches an entry outside this view.

Dependency / dependsOnGalera Cluster lists MariaDB as a dependency.
Complements / complementsGalera Cluster lists MariaDB as a complement.
Complements / complementsGalera Cluster lists ProxySQL as a complement.
Recorded use / usedByMariaDB records Galera Cluster in its usedBy list. This is a recorded use association, not an inferred dependency.
Complements / complementsMariaDB lists Galera Cluster as a complement.
Complements / complementsProxySQL lists Galera Cluster as a complement.

HAProxy Middleware

Open guide: HAProxy

13 direct recorded connections in this view. 2 further records touch entries outside this view.

Dependency / dependsOnHAProxy lists Linux as a dependency.
Alternatives / alternativesHAProxy lists Pgpool-II as an alternative.
Complements / complementsHAProxy lists Patroni as a complement.
Complements / complementsHAProxy lists keepalived as a complement.
Complements / complementsHAProxy lists PgBouncer as a complement.
Complements / complementsHAProxy lists PostgreSQL as a complement.
Complements / complementskeepalived lists HAProxy as a complement.
Recorded use / usedByLinux records HAProxy in its usedBy list. This is a recorded use association, not an inferred dependency.
Complements / complementsPatroni lists HAProxy as a complement.
Complements / complementsPgBouncer lists HAProxy as a complement.
Alternatives / alternativesPgpool-II lists HAProxy as an alternative.
Complements / complementsPostgreSQL lists HAProxy as a complement.
Alternatives / alternativesProxySQL lists HAProxy as an alternative.

Patroni Middleware

Open guide: Patroni

13 direct recorded connections in this view. 1 further record touches an entry outside this view.

Recorded use / usedByetcd records Patroni in its usedBy list. This is a recorded use association, not an inferred dependency.
Complements / complementsetcd lists Patroni as a complement.
Complements / complementsHAProxy lists Patroni as a complement.
Complements / complementskeepalived lists Patroni as a complement.
Dependency / dependsOnPatroni lists PostgreSQL as a dependency.
Dependency / dependsOnPatroni lists etcd as a dependency.
Alternatives / alternativesPatroni lists Pgpool-II as an alternative.
Complements / complementsPatroni lists HAProxy as a complement.
Complements / complementsPatroni lists keepalived as a complement.
Complements / complementsPatroni lists PgBouncer as a complement.
Complements / complementsPgBouncer lists Patroni as a complement.
Recorded use / usedByPostgreSQL records Patroni in its usedBy list. This is a recorded use association, not an inferred dependency.
Complements / complementsPostgreSQL lists Patroni as a complement.

PgBouncer Middleware

Open guide: PgBouncer

11 direct recorded connections in this view. 1 further record touches an entry outside this view.

Complements / complementsHAProxy lists PgBouncer as a complement.
Complements / complementskeepalived lists PgBouncer as a complement.
Complements / complementsPatroni lists PgBouncer as a complement.
Dependency / dependsOnPgBouncer lists PostgreSQL as a dependency.
Alternatives / alternativesPgBouncer lists Pgpool-II as an alternative.
Complements / complementsPgBouncer lists HAProxy as a complement.
Complements / complementsPgBouncer lists Patroni as a complement.
Complements / complementsPgBouncer lists keepalived as a complement.
Alternatives / alternativesPgpool-II lists PgBouncer as an alternative.
Recorded use / usedByPostgreSQL records PgBouncer in its usedBy list. This is a recorded use association, not an inferred dependency.
Complements / complementsPostgreSQL lists PgBouncer as a complement.

Pgpool-II Middleware

Open guide: Pgpool-II

8 direct recorded connections in this view.

Alternatives / alternativesHAProxy lists Pgpool-II as an alternative.
Alternatives / alternativesPatroni lists Pgpool-II as an alternative.
Alternatives / alternativesPgBouncer lists Pgpool-II as an alternative.
Dependency / dependsOnPgpool-II lists PostgreSQL as a dependency.
Alternatives / alternativesPgpool-II lists PgBouncer as an alternative.
Alternatives / alternativesPgpool-II lists HAProxy as an alternative.
Complements / complementsPgpool-II lists PostgreSQL as a complement.
Recorded use / usedByPostgreSQL records Pgpool-II in its usedBy list. This is a recorded use association, not an inferred dependency.

ProxySQL Middleware

Open relationship profile: ProxySQL

8 direct recorded connections in this view.

Complements / complementsGalera Cluster lists ProxySQL as a complement.
Recorded use / usedByMariaDB records ProxySQL in its usedBy list. This is a recorded use association, not an inferred dependency.
Complements / complementsMariaDB lists ProxySQL as a complement.
Complements / complementsMySQL lists ProxySQL as a complement.
Dependency / dependsOnProxySQL lists MariaDB as a dependency.
Alternatives / alternativesProxySQL lists HAProxy as an alternative.
Complements / complementsProxySQL lists MariaDB as a complement.
Complements / complementsProxySQL lists Galera Cluster as a complement.

keepalived Middleware

Open guide: keepalived

9 direct recorded connections in this view. 1 further record touches an entry outside this view.

Complements / complementsHAProxy lists keepalived as a complement.
Dependency / dependsOnkeepalived lists Linux as a dependency.
Complements / complementskeepalived lists HAProxy as a complement.
Complements / complementskeepalived lists Patroni as a complement.
Complements / complementskeepalived lists PgBouncer as a complement.
Recorded use / usedByLinux records keepalived in its usedBy list. This is a recorded use association, not an inferred dependency.
Complements / complementsMariaDB lists keepalived as a complement.
Complements / complementsPatroni lists keepalived as a complement.
Complements / complementsPgBouncer lists keepalived as a complement.

Observability

Braintrust Observability

Open relationship profile: Braintrust

4 direct recorded connections in this view.

Alternatives / alternativesBraintrust lists LangSmith as an alternative.
Alternatives / alternativesBraintrust lists Langfuse as an alternative.
Alternatives / alternativesLangfuse lists Braintrust as an alternative.
Alternatives / alternativesLangSmith lists Braintrust as an alternative.

LangSmith Observability

Open relationship profile: LangSmith

5 direct recorded connections in this view. 4 further records touch entries outside this view.

Alternatives / alternativesBraintrust lists LangSmith as an alternative.
Alternatives / alternativesLangfuse lists LangSmith as an alternative.
Alternatives / alternativesLangSmith lists Langfuse as an alternative.
Alternatives / alternativesLangSmith lists Braintrust as an alternative.
Complements / complementsLangSmith lists Prometheus as a complement.

Langfuse Observability

Open relationship profile: Langfuse

4 direct recorded connections in this view. 1 further record touches an entry outside this view.

Alternatives / alternativesBraintrust lists Langfuse as an alternative.
Alternatives / alternativesLangfuse lists LangSmith as an alternative.
Alternatives / alternativesLangfuse lists Braintrust as an alternative.
Alternatives / alternativesLangSmith lists Langfuse as an alternative.

Prometheus Observability

Open guide: Prometheus

5 direct recorded connections in this view.

Complements / complementsInfluxDB lists Prometheus as a complement.
Complements / complementsKubernetes lists Prometheus as a complement.
Complements / complementsLangSmith lists Prometheus as a complement.
Complements / complementsPrometheus lists Kubernetes as a complement.
Complements / complementsPrometheus lists etcd as a complement.

Systems

Containers Systems

Open relationship profile: Containers

6 direct recorded connections in this view. 2 further records touch entries outside this view.

Dependency / dependsOnContainers lists Linux as a dependency.
Recorded use / usedByContainers records Kubernetes in its usedBy list. This is a recorded use association, not an inferred dependency.
Complements / complementsContainers lists Kubernetes as a complement.
Dependency / dependsOnKubernetes lists Containers as a dependency.
Recorded use / usedByLinux records Containers in its usedBy list. This is a recorded use association, not an inferred dependency.
Complements / complementsLinux lists Containers as a complement.

Linux Systems

Open guide: Linux

35 direct recorded connections in this view. 6 further records touch entries outside this view.

Dependency / dependsOnApache Airflow lists Linux as a dependency.
Dependency / dependsOnApache Kafka lists Linux as a dependency.
Dependency / dependsOnApache Spark lists Linux as a dependency.
Dependency / dependsOnContainers lists Linux as a dependency.
Dependency / dependsOnCouchDB lists Linux as a dependency.
Dependency / dependsOnetcd lists Linux as a dependency.
Dependency / dependsOnHAProxy lists Linux as a dependency.
Dependency / dependsOnInfluxDB lists Linux as a dependency.
Dependency / dependsOnkeepalived lists Linux as a dependency.
Dependency / dependsOnKubernetes lists Linux as a dependency.
Recorded use / usedByLinux records PostgreSQL in its usedBy list. This is a recorded use association, not an inferred dependency.
Recorded use / usedByLinux records MariaDB in its usedBy list. This is a recorded use association, not an inferred dependency.
Recorded use / usedByLinux records MongoDB in its usedBy list. This is a recorded use association, not an inferred dependency.
Recorded use / usedByLinux records Kubernetes in its usedBy list. This is a recorded use association, not an inferred dependency.
Recorded use / usedByLinux records HAProxy in its usedBy list. This is a recorded use association, not an inferred dependency.
Recorded use / usedByLinux records keepalived in its usedBy list. This is a recorded use association, not an inferred dependency.
Recorded use / usedByLinux records etcd in its usedBy list. This is a recorded use association, not an inferred dependency.
Recorded use / usedByLinux records Containers in its usedBy list. This is a recorded use association, not an inferred dependency.
Recorded use / usedByLinux records MySQL in its usedBy list. This is a recorded use association, not an inferred dependency.
Recorded use / usedByLinux records CouchDB in its usedBy list. This is a recorded use association, not an inferred dependency.
Recorded use / usedByLinux records InfluxDB in its usedBy list. This is a recorded use association, not an inferred dependency.
Recorded use / usedByLinux records Memcached in its usedBy list. This is a recorded use association, not an inferred dependency.
Recorded use / usedByLinux records Qdrant in its usedBy list. This is a recorded use association, not an inferred dependency.
Recorded use / usedByLinux records Valkey in its usedBy list. This is a recorded use association, not an inferred dependency.
Recorded use / usedByLinux records Apache Kafka in its usedBy list. This is a recorded use association, not an inferred dependency.
Recorded use / usedByLinux records Apache Airflow in its usedBy list. This is a recorded use association, not an inferred dependency.
Recorded use / usedByLinux records Apache Spark in its usedBy list. This is a recorded use association, not an inferred dependency.
Complements / complementsLinux lists Containers as a complement.
Dependency / dependsOnMariaDB lists Linux as a dependency.
Dependency / dependsOnMemcached lists Linux as a dependency.
Dependency / dependsOnMongoDB lists Linux as a dependency.
Dependency / dependsOnMySQL lists Linux as a dependency.
Dependency / dependsOnPostgreSQL lists Linux as a dependency.
Dependency / dependsOnQdrant lists Linux as a dependency.
Dependency / dependsOnValkey lists Linux as a dependency.

Guides

In-depth pages, newest content first within each category.

PostgreSQL High Availabilityadvanced

Patroni, etcd, HAProxy and keepalived assembled into one topology - who decides, who routes, who owns the address, and the failover timeline.

Architecture

Read/Write Splittingadvanced

Routing reads to replicas without breaking read-after-write - where to split, the LSN token that makes it safe, and what replication lag costs you.

Architecture

RAG at Production Scaleadvanced

Retrieval topology beyond the demo - index freshness, authorisation applied before retrieval rather than after, and the corpus as a supply chain.

Architecture

RAG for Operational Reportingadvanced

A worked reference design for turning operational data - logs, metrics, alerts, tickets - into narrative reports with retrieval-augmented generation, grounded in published research rather than a specific product.

Architecture

Payment Ledger Designadvanced

Double-entry accounting as a database schema - append-only entries, idempotency keys for retried payments, derived balances, and daily reconciliation.

Architecture

Transaction Monitoring and Sanctions Screeningadvanced

AML and sanctions architecture where false-positive economics dominate - alert generation, triage, tuning as a governed change, and the audit trail.

Architecture

Data pipelinesbeginner

Batch versus streaming pipelines, ETL versus ELT, idempotent writes, backfills, and the failure modes that turn a nightly job into a week of recovery.

Data Engineering

Change data captureintermediate

Log-based change data capture - reading the database WAL instead of polling tables, Debezium and Kafka Connect, replication slots, snapshotting, and what breaks when the consumer falls behind.

Data Engineering

Streaming platformsintermediate

Apache Kafka in practice - partitioned logs, consumer groups, replication and in-sync replicas, delivery semantics, KRaft, and the operational failures that matter.

Data Engineering

Workflow orchestrationintermediate

Apache Airflow in practice - DAGs as code, scheduling semantics and the data interval, retries and SLAs, backfills, and when an orchestrator earns its place over a cron job.

Data Engineering

Lakehouse and table formatsadvanced

Open table formats on object storage - Parquet as the columnar file layer, Apache Iceberg's snapshot model, schema and partition evolution, time travel, and how Iceberg compares with Delta Lake and Hudi.

Data Engineering

Data qualityintermediate

Data quality in practice - data contracts, schema and distribution checks, freshness and volume monitoring, where testing sits in the pipeline, and why a green pipeline run is not a quality signal.

Data Engineering

Data warehousingintermediate

Data warehouse architecture in practice - warehouse versus lake versus lakehouse, MPP and columnar storage, star schema modelling with facts and dimensions, slowly changing dimensions, and where warehouses fit in a modern stack.

Data Engineering

Apache Sparkintermediate

Apache Spark in practice - driver and executors, lazy evaluation and the DAG of stages, shuffles, partitions, Structured Streaming, and the failure modes that make Spark jobs slow or dead.

Data Engineering

dbtintermediate

dbt in practice - models and ref(), materializations, tests, snapshots for slowly changing dimensions, sources and freshness, and why dbt is a transformation layer, not an orchestrator.

Data Engineering

Schema registryintermediate

Schema registries and schema evolution in practice - why a topic needs a declared shape, Avro/Protobuf/JSON Schema, compatibility modes, the wire format, and what breaks when evolution rules are bypassed.

Data Engineering

PostgreSQLintermediate

PostgreSQL internals that decide production behaviour - MVCC and XID wraparound, autovacuum thresholds, work_mem, WAL durability, indexes, replication.

Databases

PostgreSQL 17 Installation and Configurationbeginner

Installing PostgreSQL 17 on Ubuntu/Debian, RHEL/Rocky/AlmaLinux, Windows and macOS, with the postgresql.conf and pg_hba.conf settings to review before anything connects to it.

Databases

PostgreSQL 19 - what changes and what breaksintermediate

PostgreSQL 19 release status, an overview of every feature area - REPACK, WAIT and sequence replication, parallel and scored autovacuum, plan advice, I/O autoscaling, the monitoring additions and the new SQL surface - and the full list of migration breakers to check before upgrading.

Databases

PostgreSQL REPACK - reclaiming space without the lockintermediate

How PostgreSQL reclaims dead-tuple space by rewriting a table - the pg_repack extension's trigger-and-log-table mechanism that carried PG 15-18, and the native REPACK command landing in PG 19 that replaces the trigger with logical decoding.

Databases

PostgreSQL 19 replication - WAIT, sequences and subscriptionsintermediate

PostgreSQL 19's replication changes - the WAIT command for read-your-writes on standbys, logical replication of sequences, the publication EXCEPT clause, retain_dead_tuples conflict detection, and wal_level replica gaining logical capability on demand.

Databases

PostgreSQL 19 autovacuum - parallel workers and the scoring systemintermediate

What PostgreSQL 19 changes in autovacuum - parallel index vacuuming controlled by autovacuum_max_parallel_workers, a five-component scoring system that decides which tables get vacuumed first, and the new monitoring surface around it.

Databases

MariaDBintermediate

MariaDB Server in practice - where it has diverged from MySQL, choosing a storage engine, InnoDB durability settings, replication, and Galera's real cost.

Databases

PostgreSQL 19 asynchronous I/O - worker autoscaling and read-aheadintermediate

What PostgreSQL 19 changes in the asynchronous I/O subsystem that arrived in 18 - I/O workers that scale themselves between io_min_workers and io_max_workers, better read-ahead scheduling for large requests, and the EXPLAIN IO output that shows it working.

Databases

PostgreSQL 19 monitoring - new views, wait events and log controlsintermediate

A diagnostic runbook for what PostgreSQL 19 adds to the monitoring surface - pg_stat_lock, pg_stat_recovery, new wait events, per-process-type log levels, stats_reset columns, WAL full-page-image bytes and the wraparound warning change - with the queries to use them.

Databases

PostgreSQL 19 plan advice - pg_plan_advice and pg_stash_adviceadvanced

PostgreSQL 19's answer to plan instability - the pg_plan_advice module that turns planner decisions into an editable advice string, and pg_stash_advice which applies that advice automatically per query ID, with the failure modes of each.

Databases

PostgreSQL 19 - new SQL and COPY surfaceintermediate

The SQL surface PostgreSQL 19 adds - INSERT ON CONFLICT DO SELECT, window IGNORE NULLS, COPY TO JSON and partitioned tables, GRANTED BY, CHECK constraint enforcement toggles, oid8, jsonpath methods and the new encodings. Performance and I/O changes have their own page.

Databases

PostgreSQL 19 maintenance extensions - pg_visibility, pg_surgery, pg_prewarm, pgrowlocksadvanced

The contrib modules that inspect and repair what PostgreSQL 19's maintenance changes touch - pg_visibility for the visibility map that scans now write, pgrowlocks for per-row lock detail under pg_stat_lock, pg_surgery for the corruption cases that block vacuum, and pg_prewarm for cache warmup. None changed in 19; all are more relevant because of it.

Databases

MySQLintermediate

MySQL in production - InnoDB buffer pool, redo and undo, REPEATABLE READ and gap locks, GTIDs and Group Replication, and the 8.4 default changes.

Databases

MongoDBintermediate

Document modelling as physical design, replica set write and read concerns, shard key selection, compound index prefixes, and the aggregation pipeline.

Databases

SQL Serverintermediate

SQL Server edition limits that decide architecture - memory and core caps, Always On versus FCI, RCSI and tempdb, Query Store, core-based licensing.

Databases

pgvectorintermediate

Vector similarity search in PostgreSQL - where the data physically lives across heap, TOAST and index, how HNSW and IVFFlat retrieve it, and how pgvector serves as the memory layer in a RAG or agent system.

Databases

DynamoDBintermediate

Amazon DynamoDB in practice - the partition key contract, consistency options, secondary indexes, transactions, and what throttling actually means.

Databases

TimescaleDBintermediate

TimescaleDB as a PostgreSQL extension - hypertables and chunks, continuous aggregates, compression, retention, and what being an extension buys and costs.

Databases

InfluxDBintermediate

InfluxDB 3 in practice - measurement/tag/field model, the Arrow rebuild, SQL querying, Core versus Enterprise, and tag cardinality as the classic way to take it down.

Databases

CouchDBintermediate

Apache CouchDB in practice - MVCC revision tokens, bidirectional replication as the core feature, Mango queries and views, and multi-master conflict reality.

Databases

Milvusintermediate

Milvus in practice - collections and partitions, index types for vector search, tunable consistency, the disaggregated Kubernetes architecture, and what running it actually costs.

Databases

Memcachedintermediate

Memcached in practice - the slab allocator, LRU eviction, client-side sharding, the cas primitive, and why having no replication is a feature.

Databases

Snowflakeintermediate

Snowflake in practice - storage/compute separation, micro-partitions and pruning, virtual warehouses, zero-copy clone, time travel, and the consumption billing model that shapes everything.

Databases

Oracle Databaseintermediate

Oracle Database in practice - the converged engine, CDB/PDB multitenancy, RAC shared-everything scaling, Data Guard, and the licensing reality that shapes every decision.

Databases

Qdrantintermediate

Qdrant in practice - collections and points, HNSW plus quantisation, payload-filtered search, cluster mode with Raft, and why it is the middle ground between pgvector and Milvus.

Databases

Valkeyintermediate

Valkey in practice - the Linux Foundation Redis fork, wire compatibility, what diverged since 7.2, the migration path, and when to pick it over Redis.

Databases

Choosing a relational databaseintermediate

PostgreSQL, MySQL, MariaDB or SQL Server. Operational expertise, licence cost and the one feature you actually need decide it, not the feature matrix.

Decision Guides

Pooling and failover topologyintermediate

PgBouncer, Pgpool-II, or PgBouncer with Patroni and HAProxy. Which of pooling, read routing and automatic promotion you actually need decides it.

Decision Guides

Choosing a vector storeintermediate

pgvector, Qdrant, Weaviate or Elasticsearch. Whether you already run PostgreSQL, and how you filter, decide it - not throughput charts.

Decision Guides

PgBouncerintermediate

PostgreSQL connection pooling with PgBouncer - pool modes and what each one breaks, sizing the pool, secure auth_query, and running it multi-core.

Middleware

Pgpool-IIintermediate

Pgpool-II in practice - clustering modes, how load balancing decides where a SELECT goes, watchdog quorum, failover, and the diagnostics.

Middleware

Patroniadvanced

How Patroni fails PostgreSQL over - the DCS leader lock, the ttl/loop_wait/retry_timeout rule, watchdog fencing, and a runnable three-node config.

Middleware

keepalivedintermediate

VRRP master election in keepalived - a runnable two-node config, the weight arithmetic people get wrong, and why it fails on cloud networks.

Middleware

HAProxy for PostgreSQLadvanced

A runnable HAProxy configuration for a three-node Patroni cluster - mode tcp, Patroni HTTP health checks, timeouts for long-lived sessions, and draining.

Middleware

etcdadvanced

Raft, quorum and leases in etcd, the fsync latency budget that decides cluster stability, and the space-quota outage - compaction, defragmentation, recovery.

Middleware

Prometheusadvanced

The pull model, why a label set defines a time series and cardinality kills servers, histogram versus summary, rate() correctly, and Alertmanager routing.

Middleware