Re: Optimize postgres protocol for fixed size arrays
От | ktm@rice.edu |
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Тема | Re: Optimize postgres protocol for fixed size arrays |
Дата | |
Msg-id | 20111122215806.GP27589@staff-mud-56-27.rice.edu обсуждение исходный текст |
Ответ на | Optimize postgres protocol for fixed size arrays (Mikko Tiihonen <mikko.tiihonen@nitorcreations.com>) |
Список | pgsql-hackers |
On Tue, Nov 22, 2011 at 11:47:22PM +0200, Mikko Tiihonen wrote: > Hi, > > During conversion of the jdbc driver to use binary encoding when receiving array objects from postgres it was noticed > that for example for int[] arrays the binary encoding is normally 30% to 200% larger in bytes than the text encoding. > > This was of concern to some users with slower links to database. Even though the encoded size was larger the binary > encoding was still constantly faster (with 50% speed up for float[]). > > Here is a patch that adds a new flag to the protocol that is set when all elements of the array are of same fixed size. > When the bit is set the 4 byte length is only sent once and not for each element. Another restriction is that the flag > can only be set when there are no NULLs in the array. > Cool. This would be very useful with the DSPAM binary array driver. Although the binary is shorter because the values are 8 byte integers, they would be much shorter without the redundant sizing information. Barring issues: +1 Regards, Ken
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