PostgreSQL performance findings — query plans, index trade-offs, and planner behavior, measured at real data scales.https://exobench.aien-usAlexander Ioffehttps://exobench.ai/blog/covering-index-write-costhttps://exobench.ai/blog/covering-index-write-cost'Covering indexes hurt your writes' is an architectural maxim with no number attached. Here is the number: +28% on INSERTs, +25% on UPDATEs, 1.26x faster reads, and covering wins below ~4,300 writes per analytical read. Measured on PostgreSQL 17 at 2M rows.Mon, 17 Aug 2026 00:00:00 GMTAlexander Ioffesqloptimizationpostgresindexescovering-indexexplain-analyzewrite-amplificationAlexander Ioffehttps://exobench.ai/blog/jsonb-paths-or-gin-or-columnshttps://exobench.ai/blog/jsonb-paths-or-gin-or-columnsColumns beat JSONB+GIN at everything except multi-key containment on PostgreSQL 17Mon, 17 Aug 2026 00:00:00 GMTAlexander Ioffesqloptimizationpostgresexplain-analyzejsonbindexingAlexander Ioffehttps://exobench.ai/blog/pg19-graph-queries-part-1https://exobench.ai/blog/pg19-graph-queries-part-1Postgres 19 adds SQL/PGQ graph queries. Measured against a PostgreSQL 19beta1 build, the fixed-depth graph query compiles to the exact same plan as a hand-written join, and the variable-depth traversal that graph databases were built for still falls to a recursive CTE. Apache AGE runs the same indexed traversal under a Cypher wrapper. Numbers from ExoBench in local mode.Mon, 17 Aug 2026 00:00:00 GMTAlexander Ioffepostgrespostgres-19graphsql-pgqgraph-tableapache-agerecursive-cteexplain-analyzeneo4jAlexander Ioffehttps://exobench.ai/blog/postgres-default-from-2002https://exobench.ai/blog/postgres-default-from-2002...because your vendor's Cost Model Is from 2002. Since random_page_cost = 4.0 is for spinning disks and hasn't changed in 25 years, setting it to 1.1 cuts this query from 125.98ms to 68.69ms.Mon, 17 Aug 2026 00:00:00 GMTAlexander Ioffesqloptimizationpostgresexplain-analyzeplannerrandom_page_costAlexander Ioffe