115 articles · 35 databases · 63 topics
Practical tutorials, performance tuning and internals for SQL Server, PostgreSQL, MySQL, MongoDB, Redis and every engine in between — written by people who run them in production.
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RelationalMicrosoft's enterprise relational database engine.
30 articles →
RelationalThe world's most advanced open-source relational database.
16 articles →
RelationalThe popular open-source database behind much of the web.
10 articles →
RelationalThe long-standing heavyweight of enterprise data.
9 articles →
EmbeddedA tiny, serverless SQL engine inside everything.
8 articles →
DocumentA document database built around flexible JSON-like documents.
6 articles →
Key-valueIn-memory data structures at microsecond speed.
2 articles →
Wide-columnMasterless, linearly scalable wide-column store.
3 articles →
Editor's picks
ClickHouseIntermediateTOO_MANY_PARTS means too many small inserts, not too much data. Batch your writes, turn on async inserts, and stop over-partitioning your MergeTree tables.
In this article
· 7 min read
PostgreSQLIntermediateRaising max_connections to 1000 usually makes things worse. Learn why Postgres connections are expensive, where they're leaking and how PgBouncer fixes it for good.
#configuration#performance#troubleshooting
PostgreSQLBeginnerThe index exists, but the plan still shows a scan. Nine common reasons the optimizer can't (or shouldn't) use your index, and how to fix each one.
#execution-plans#indexing#performance
Fresh commits
SQL ServerIntermediateQuery sys.dm_db_missing_index_details and its companion DMVs, read the numbers critically, find the queries behind each suggestion and merge them into the few indexes worth creating.
#db-administration#execution-plans#indexing
SQL ServerAdvancedA table-by-table workflow for tuning existing SQL Server indexes: find unused and overlapping indexes, merge them, and replace blanket rebuilds with statistics updates.
#db-administration#indexing#maintenance
RedisIntermediateWrites fail and reads still work. Understand Redis eviction policies, find what's filling memory, and pick the right fix depending on whether Redis is a cache or a datastore.
#caching#configuration#nosql
PostgreSQLBeginnerA founder's guide to choosing PostgreSQL or MySQL: team experience, managed hosting, scaling paths, extensions, licensing, switching cost, and a clear "pick PostgreSQL unless" rule.
#db-administration#scalability#schema-design
PostgreSQLBeginnertimestamptz doesn't store a time zone, and timestamp silently drops the offset you pass in. What each type really stores, where timestamp causes bugs and the one case where it's right.
#data-types#schema-design
Learning paths
LEVEL 01
Tables, keys, joins and your first indexes. Build intuition that lasts.
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LEVEL 02
Query plans, transactions, replication and schema design trade-offs.
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LEVEL 03
Storage engines, concurrency control, internals and extreme tuning.
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