[pgpool-general: 8559] Re: write_function_list in 4.2 - can we use separators?

Tatsuo Ishii ishii at sraoss.co.jp
Wed Jan 25 14:39:51 JST 2023


> Hi
> 
> According to the docs, "write_function_list" in 4.2 is not "schema sensitive"
> https://www.pgpool.net/docs/42/en/html/runtime-config-load-balancing.html#GUC-WRITE-FUNCTION-LIST
> 
> This is a change from 4.1  in which the same parameter (called
> balc_function_list) was not "schema sensitive"
> https://www.pgpool.net/docs/41/en/html/runtime-config-load-balancing.html#GUC-BLACK-FUNCTION-LIST
> 
> Since I have a long list of data modifying function prefixes and I
> also have several schemas where they may exist the following now has
> to be expanded:
> write_function_list =
> 'currval,lastval,nextval,setval,convert_.*,create_.*,delete_.*,handle_.*,insert_.*,mark_.*,move_.*,process_.*,purge_.*,selsert_.*,update_.*,upgrade_.*
> ,merge_.*'
> 
> For example, "merge_.*" now has to be
> "merge_.*,schema1.merge_.*,schema2.merge_.*,schema3.merge_.*"
> This is going to be rather ....interesting... to manage...
> 
> My question is:
> Can I use *spaces*, *tabs* and/or *newlines* to "break apart" this
> config parameter so its easier to manage in pgpool.conf?
> Something like following (but only with example for merge_ shown to
> reduce verbosity):

You can use spaces, tabs, but you cannot use newlines.

BTW, why don't use the new feature of 4.2?

-----------------------------------------------------------------
read_only_function_list (string)
:
:
Note: If this parameter and write_function_list is empty string,
function's volatile proper will be checked. If the property is
volatile, the function is regarded as a writing function. This is
convenient and recommended way. However this requires one extra query
against system catalog for the first time (in the next time cached
query result is used and no extra query will be sent). If you don't
want to send such query, you can keep on using this parameter.
-----------------------------------------------------------------

By setting:

read_only_function_list = ''
write_function_list = ''

Pgpool-II will automatically find write functions by looking at the
function's volatile property. If it is "VOLATILE", that means the
function writes something and should be sent to primary node only.

Best reagards,
--
Tatsuo Ishii
SRA OSS LLC
English: http://www.sraoss.co.jp/index_en/
Japanese:http://www.sraoss.co.jp


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