[Pgpool-hackers] patch "Caching query results in pgpool-II"

[Masanori Yamazaki]

> So where is new document patch?

I'm sending new document patch.
I described the way to install memcached or libmemcached(c client library)
for memcached users.


regards
Masanori YAMAZAKI


2011/6/19 Tatsuo Ishii <ishii at sraoss.co.jp>

> Forgot to attach patches.
> --
> Tatsuo Ishii
> SRA OSS, Inc. Japan
> English: http://www.sraoss.co.jp/index_en.php
> Japanese: http://www.sraoss.co.jp
>
> >> 2011/6/14 Tatsuo Ishii <ishii at sraoss.co.jp>
> >>
> >>> Please explain what is implemented and what is not implemented in this
> >>> patch.
> >>>
> >>
> >> What is implemented in this patch are as below.
> >> - connect to memcached.
> >> - set RowDescription or DataRow on memcached.
> >> - get RowDescription or DataRow on memcached by using key of md5(SELECT
> >> convert).
> >> - delete cache on memcached by using key of md5(SELECT convert). only
> >> module.
> >> - fetch and parse the fellowing data in pgpool.conf.
> >>
> >> memory_cache_enabled
> >> memqcache_method
> >> memqcache_memcached_host
> >> memqcache_memcached_port
> >> memqcache_total_size
> >> memqcache_expire
> >> memqcache_maxcache
> >> memqcache_cache_block_size
> >>
> >> - add data to buffer before set data on memcached.
> >> - get buffer in order to set it on memcached
> >> - initialize buffer
> >>
> >> I am implemented only in Simple Query case.
> >>
> >>
> >> What is not implemented in this patch are as below.
> >> - shmem cache.
> >> structure of  managing table oids.
> >> the space management map.
> >> on memory query cache structure.
> >>
> >> - implementation in Extended Query case.
> >>
> >> - cache validation.
> >> The result of SELECT using none IMMUTABLE functions is not cached.
> >
> > I have made a patch to implement a function which checks if a SELECT
> > statement includes non IMMUTABLE function call.
> >
> > extern bool pool_has_non_immutable_function_call(Node *node);
> >
> > See attached patches.
> >
> > TODO:
> >
> > Some statements including:
> >
> > SELECT current_timestamp;
> >
> > is not detected by the function even if it uses IMMUTABLE function
> > because it is translated to a non function form. Obviously we should
> > not cache the result of current_timestamp. What should we do? Probably
> > we have to have a heuristics to detect the particular form?
> >
> >> - remove cache
> >> If cache is full, the least recently used cache is removed.
> >> If a table is dropped or modified, related cache data is deleted.
> >> If a table definition is modified(ALTER TABLE), related cache data is
> >> deleted.
> >> If a schema or database is dropped, related cache data is deleted.
> >>
> >>
> >> This week I am mainly implementing the shmem cache.
> >>
> >> Regards
> >> Masanori YAMAZAKI
> >>
> >>
> >>
> >>
> >>> --
> >>> Tatsuo Ishii
> >>> SRA OSS, Inc. Japan
> >>> English: http://www.sraoss.co.jp/index_en.php
> >>> Japanese: http://www.sraoss.co.jp
> >>>
> >>> > Hello, hackers
> >>> >
> >>> > I have implemented a function caching query on memcached.
> >>> > I am sending the patch file and it's so nice to give me some
> opinions.
> >>> >
> >>> > Main program which I implemented is as below.
> >>> > - Search for cache data on memcached by using md5 which converted
> SELECT
> >>> > into.
> >>> > - Set data on memcached. The key is md5 which converted  SELECT into.
> >>> > The value is RowDescription, DataRow from Backend.
> >>> >
> >>> > [Modify files]
> >>> > - pool.h
> >>> > - child.c
> >>> > - pool_config.l
> >>> > - pool_config.h
> >>> > - pool_config.c
> >>> > - pool_system.c
> >>> > - pool_proto_modules.c
> >>> > - pool_process_query.c
> >>> >
> >>> > [New File]
> >>> > - pool_memqcache.c
> >>> >
> >>> >
> >>> > --
> >>> > Regards
> >>> > Masanori YAMAZAKI
> >>>
>



-- 
best regards
Masanori YAMAZAKI
email: m.yamazaki23 at gmail.com
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://pgfoundry.org/pipermail/pgpool-hackers/attachments/20110619/d271a418/attachment.html>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: doc.patch
Type: text/x-patch
Size: 8546 bytes
Desc: not available
URL: <http://pgfoundry.org/pipermail/pgpool-hackers/attachments/20110619/d271a418/attachment.bin>