The document discusses using Statspack and AWR (Automatic Workload Repository) to analyze SQL performance and identify poorly performing queries. It provides examples of Statspack reports and how to interpret them to find SQL statements that are doing full table scans, experiencing buffer cache misses, or are inefficient due to lack of bind variables. The document also discusses how to identify SQL statements that are causing excessive sorting.

1. Michael R. Ault Oracle Guru Texas Memory Systems Using AWR For SQL Analysis

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32. Sort Statistics Statistic Total per Second per Trans -------------------------------- ------------------ -------------- ------------- sorts (disk) 3,529 0.2 0.0 sorts (memory) 9,012,270 417.6 6.0 sorts (rows) 110,063,794,220 5,099,850.2 73,302.3 workarea executions - multipass 0 0.0 0.0 workarea executions - onepass 5,293 0.3 0.0 workarea executions - optimal 7,113,060 329.6 4.7 Tablespace IO Stats DB/Inst: CC1/cc1 Snaps: 84084-84108 -> ordered by IOs (Reads + Writes) desc Tablespace ------------------------------ Av Av Av Av Buffer Av Buf Reads Reads/s Rd(ms) Blks/Rd Writes Writes/s Waits Wt(ms) -------------- ------- ------ ------- ------------ -------- ---------- ------ TEMP 11,484,000 532 16.3 4.1 3,478,365 161 12,266 2.0 REPMAN_TEMP 1,703,767 79 27.2 8.2 1,457,241 68 0 0.0

33. Sort Statistics PGA Aggr Target Histogram DB/Inst: test/test Snaps: 84-108 -> Optimal Executions are purely in-memory operations Low High Optimal Optimal Total Execs Optimal Execs 1-Pass Execs M-Pass Execs ------- ------- -------------- -------------- ------------ ------------ 2K 4K 6,308,435 6,308,435 0 0 512K 1024K 353,344 353,344 0 0 1M 2M 201,558 201,558 0 0 2M 4M 22,468 22,468 0 0 4M 8M 21,796 21,725 71 0 8M 16M 28,892 28,714 178 0 16M 32M 30,478 30,346 132 0 32M 64M 19,898 18,690 1,208 0 64M 128M 9,080 7,284 1,796 0 128M 256M 1,682 732 950 0 256M 512M 734 179 555 0 512M 1024M 329 58 271 0 1G 2G 131 14 117 0 2G 4G 17 4 13 0 -------------------------------------------------------------

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