Old-style OR indexscan slated for destruction

Started by Tom Laneover 20 years ago5 messages
#1Tom Lane
tgl@sss.pgh.pa.us

I am about to rip out the code that supports multiple indexscans for OR
conditions inside a single IndexScan plan node. As best I can tell,
the new-style bitmap-OR code is as fast or faster than the old way
even in fully cached test cases (ie, with no allowance for improved
efficiency of disk access). So there's no percentage in maintaining
support for the old way, and getting rid of it will allow simplification
of code and data structures in the planner.

regards, tom lane

#2Oleg Bartunov
oleg@sai.msu.su
In reply to: Tom Lane (#1)
Re: Old-style OR indexscan slated for destruction

On Sun, 24 Apr 2005, Tom Lane wrote:

I am about to rip out the code that supports multiple indexscans for OR
conditions inside a single IndexScan plan node. As best I can tell,
the new-style bitmap-OR code is as fast or faster than the old way
even in fully cached test cases (ie, with no allowance for improved
efficiency of disk access). So there's no percentage in maintaining
support for the old way, and getting rid of it will allow simplification
of code and data structures in the planner.

very good, Tom !

regards, tom lane

---------------------------(end of broadcast)---------------------------
TIP 6: Have you searched our list archives?

http://archives.postgresql.org

Regards,
Oleg
_____________________________________________________________
Oleg Bartunov, sci.researcher, hostmaster of AstroNet,
Sternberg Astronomical Institute, Moscow University (Russia)
Internet: oleg@sai.msu.su, http://www.sai.msu.su/~megera/
phone: +007(095)939-16-83, +007(095)939-23-83

#3Christopher Kings-Lynne
chriskl@familyhealth.com.au
In reply to: Oleg Bartunov (#2)
Re: Old-style OR indexscan slated for destruction

I am about to rip out the code that supports multiple indexscans for OR
conditions inside a single IndexScan plan node. As best I can tell,
the new-style bitmap-OR code is as fast or faster than the old way
even in fully cached test cases (ie, with no allowance for improved
efficiency of disk access). So there's no percentage in maintaining
support for the old way, and getting rid of it will allow simplification
of code and data structures in the planner.

For all index types? Even lossy ones?

Chris

#4Tom Lane
tgl@sss.pgh.pa.us
In reply to: Christopher Kings-Lynne (#3)
Re: Old-style OR indexscan slated for destruction

Christopher Kings-Lynne <chriskl@familyhealth.com.au> writes:

I am about to rip out the code that supports multiple indexscans for OR
conditions inside a single IndexScan plan node. As best I can tell,
the new-style bitmap-OR code is as fast or faster than the old way
even in fully cached test cases (ie, with no allowance for improved
efficiency of disk access). So there's no percentage in maintaining
support for the old way, and getting rid of it will allow simplification
of code and data structures in the planner.

For all index types? Even lossy ones?

Can't see that a lossy index would make any difference ...

regards, tom lane

#5Christopher Kings-Lynne
chriskl@familyhealth.com.au
In reply to: Tom Lane (#4)
Re: Old-style OR indexscan slated for destruction

For all index types? Even lossy ones?

Can't see that a lossy index would make any difference ...

OK, was just checking :)