Re: Patch: Optimize memory allocation in function 'bringetbitmap' - Mailing list pgsql-hackers

From Jinyu Zhang
Subject Re: Patch: Optimize memory allocation in function 'bringetbitmap'
Date
Msg-id 2ea866d6.5fd.15071cf2a8e.Coremail.beijing_pg@163.com
Whole thread Raw
In response to Re: Patch: Optimize memory allocation in function 'bringetbitmap'  (Alvaro Herrera <alvherre@2ndquadrant.com>)
Responses Re: Patch: Optimize memory allocation in function 'bringetbitmap'  (Tomas Vondra <tomas.vondra@2ndquadrant.com>)
Re: [HACKERS] Patch: Optimize memory allocation in function'bringetbitmap'  (Alvaro Herrera <alvherre@2ndquadrant.com>)
List pgsql-hackers


Update the patch_brin_optimze_mem according to your comment. 




At 2015-10-16 10:13:35, "Alvaro Herrera" <alvherre@2ndquadrant.com> wrote: >zhangjinyu wrote: > >> >>>>However I wonder if it would be simpler to have the dtup structure have >> >>>>the pointers, so that you can pass it as NULL in the first call and then >> >>>>followup calls reuse the one allocated in the first call. >> Jinyu: the memory is allocated from perRangeCxt and perRangeCxt will be >> reset in loop, >> so this way don't work. > >You're right. I think we can do better: have brin_deform_tuple accept >another argument of type BrinMemTuple *, which can be NULL. If NULL, >the function calls brin_new_memtuple to allocate a new one (just like >current code); if not NULL, that one is used. Have brin_new_memtuple >also allocate the values/allnulls/hasnulls arrays, which are now part of >the BrinMemTuple struct. Then, bringetbitmap calls brin_new_memtuple >once before changing to perRangeCxt, then reuse the returned inside the >loop (we probably need brin_memtuple_initialize to clear out the struct >at the end of each loop iteration). Other callers of brin_deform_tuple >just pass NULL to get the current behavior. > >-- >Álvaro Herrera http://www.2ndQuadrant.com/ >PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services > > >-- >Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) >To make changes to your subscription: >http://www.postgresql.org/mailpref/pgsql-hackers


 

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