Re: [HACKERS] Cached plans and statement generalization - Mailing list pgsql-hackers

From Heikki Linnakangas
Subject Re: [HACKERS] Cached plans and statement generalization
Date
Msg-id e9cce21f-942f-31f4-54e4-ace7f2de1a5f@iki.fi
Whole thread Raw
In response to Re: [HACKERS] Cached plans and statement generalization  (Konstantin Knizhnik <k.knizhnik@postgrespro.ru>)
Responses Re: [HACKERS] Cached plans and statement generalization  (Konstantin Knizhnik <k.knizhnik@postgrespro.ru>)
Re: [HACKERS] Cached plans and statement generalization  (Konstantin Knizhnik <k.knizhnik@postgrespro.ru>)
List pgsql-hackers
On 09/07/2019 23:59, Konstantin Knizhnik wrote:
> Fixed patch version of the path is attached.

Much of the patch and the discussion has been around the raw parsing, 
and guessing which literals are actually parameters that have been 
inlined into the SQL text. Do we really need to do that, though? The 
documentation mentions pgbouncer and other connection poolers, where you 
don't have session state, as a use case for this. But such connection 
poolers could and should still be using the extended query protocol, 
with Parse+Bind messages and query parameters, even if they don't use 
named prepared statements. I'd want to encourage applications and 
middleware to use out-of-band query parameters, to avoid SQL injection 
attacks, regardless of whether they use prepared statements or cache 
query plans. So how about dropping all the raw parse tree stuff, and 
doing the automatic caching of plans based on the SQL string, somewhere 
in the exec_parse_message? Check the autoprepare cache in 
exec_parse_message(), if it was an "unnamed" prepared statement, i.e. if 
the prepared statement name is an empty string.

(I'm actually not sure if exec_parse/bind_message is the right place for 
this, but I saw that your current patch did it in exec_simple_query, and 
exec_parse/bind_message are the equivalent of that for the extended 
query protocol).

- Heikki



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