117 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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SupabaseBeginnerNo error, just []. It's almost always Row Level Security. How RLS policies work, how to write and test them, and why the service role key is never the fix.
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SQL ServerIntermediateHow to measure SQL Server query performance with Query Store, DMVs and Extended Events, pick targets by total resource use, and check the settings that affect every query.
#configuration#db-administration#execution-plans
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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.
#configuration#performance#troubleshooting
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
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
