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Andres Freund 141fd1b66c Improve sys/catcache performance. ... The following are the individual improvements: 1) Avoidance of FunctionCallInfo based function calls, replaced by more efficient functions with a native C argument interface. 2) Don't extract columns from a cache entry's tuple whenever matching entries - instead store them as a Datum array. This also allows to get rid of having to build dummy tuples for negative & list entries, and of a hack for dealing with cstring vs. text weirdness. 3) Reorder members of catcache.h struct, so imortant entries are more likely to be on one cacheline. 4) Allowing the compiler to specialize critical SearchCatCache for a specific number of attributes allows to unroll loops and avoid other nkeys dependant initialization. 5) Only initializing the ScanKey when necessary, i.e. catcache misses, greatly reduces cache unnecessary cpu cache misses. 6) Split of the cache-miss case from the hash lookup, reducing stack allocations etc in the common case. 7) CatCTup and their corresponding heaptuple are allocated in one piece. This results in making cache lookups themselves roughly three times as fast - full-system benchmarks obviously improve less than that. I've also evaluated further techniques: - replace open coded hash with simplehash - the list walk right now shows up in profiles. Unfortunately it's not easy to do so safely as an entry's memory location can change at various times, which doesn't work well with the refcounting and cache invalidation. - Cacheline-aligning CatCTup entries - helps some with performance, but the win isn't big and the code for it is ugly, because the tuples have to be freed as well. - add more proper functions, rather than macros for SearchSysCacheCopyN etc., but right now they don't show up in profiles. The reason the macro wrapper for syscache.c/h have to be changed, rather than just catcache, is that doing otherwise would require exposing the SysCache array to the outside. That might be a good idea anyway, but it's for another day. Author: Andres Freund Reviewed-By: Robert Haas Discussion: https://postgr.es/m/20170914061207.zxotvyopetm7lrrp@alap3.anarazel.de		8 years ago
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adt	Replace remaining uses of pq_sendint with pq_sendint{8,16,32}.	8 years ago
cache	Improve sys/catcache performance.	8 years ago
error	Reduce excessive dereferencing of function pointers	8 years ago
fmgr	Replace binary search in fmgr_isbuiltin with a lookup array.	8 years ago
hash	Remove broken and useless entry-count printing in HASH_DEBUG code.	9 years ago
init	Remove replacement selection sort.	8 years ago
mb	Add more efficient functions to pqformat API.	8 years ago
misc	Basic partition-wise join functionality.	8 years ago
mmgr	Rewrite strnlen replacement implementation from 8a241792f9.	8 years ago
resowner	Remove unnecessary PG_TRY overhead for CurrentResourceOwner changes.	8 years ago
sort	Remove replacement selection sort.	8 years ago
time	Fix low-probability loss of NOTIFY messages due to XID wraparound.	8 years ago
.gitignore	Generate fmgr prototypes automatically	9 years ago
Gen_dummy_probes.pl	Update copyright via script for 2017	9 years ago
Gen_dummy_probes.sed	Update copyright via script for 2017	9 years ago
Gen_fmgrtab.pl	Replace binary search in fmgr_isbuiltin with a lookup array.	8 years ago
Makefile	Replace binary search in fmgr_isbuiltin with a lookup array.	8 years ago
errcodes.txt	Revert to 9.6 treatment of ALTER TYPE enumtype ADD VALUE.	8 years ago
generate-errcodes.pl	Clean up Perl code according to perlcritic	9 years ago
probes.d	Rename dtrace probes for ongoing xlog -> wal conversion.	9 years ago