Avoid pointer chasing in _bt_readpage inner loop. Make _bt_readpage pass down the current scan direction to various utility functions within its pstate variable. Also have _bt_readpage work off of a local copy of scan->ignore_killed_tuples within its per-tuple loop (rather than using scan->ignore_killed_tuples directly).
Testing has shown that this significantly benefits large range scans, which are naturally able to take full advantage of the pstate.startikey optimization added by commit 8a510275. Running a pgbench script with a "SELECT abalance FROM pgbench_accounts WHERE aid BETWEEN ..." query shows an increase in transaction throughput of over 5%. There also appears to be a small performance benefit when running pgbench's built-in select-only script. Follow-up to commit 65d6acbc. Author: Peter Geoghegan <[email protected]> Reviewed-By: Victor Yegorov <[email protected]> Discussion: https://postgr.es/m/cah2-wzmwmwcwkfgaf+mypwiz3il4aqpxnwtw_o0vqpwpxro...@mail.gmail.com Branch ------ master Details ------- https://git.postgresql.org/pg/commitdiff/83a26ba59b1819cbd61705a3ff6aa572081ccc4b Modified Files -------------- src/backend/access/nbtree/nbtreadpage.c | 19 ++++++++++--------- 1 file changed, 10 insertions(+), 9 deletions(-)
