Re: Beta 1.6: Output Headers refresh in slow motion

["Dave Page" <dpage(at)vale-housing(dot)co(dot)uk>]

 

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From: Harald Armin Massa [mailto:haraldarminmassa(at)gmail(dot)com]
Sent: 15 September 2006 16:57
To: Dave Page
Cc: pgadmin-support(at)postgresql(dot)org
Subject: Re: [pgadmin-support] Beta 1.6: Output Headers refresh in slow motion

Same "slow motion" is happening on resizing the output pane panel. 
 

What's happening is that when the grid control redraws itself, it asks the dataset what the header labels should be. The dataset then queries the database to get the correct typename (because libpq's PGresult only stores the type OIDs) for each column.

Hmmm.... isn't the relation type OID -> type fixed for every given instance of a database?
Maybe it would be even quicker to have a local cache of

typeOID -> typeName

So even new queries will get their column headers quick 

 

Aside from the non-trivial architectural changes this would require, there are also cache invalidation issues to consider - one instance of pgAdmin can use multiple connections to the same database, each of which would need it's own cache and even tracking and invalidating them would be difficult, never mind changes from other developers (in fact, they would require at least one query per cache access to check for changes anyway).
  

Maybe something could be could be done for 1.8, but not for 1.6. 

>I've committed a fix that will cache the type names as they are requested so that after the >initial display, subsequent redraws won't cause any queries to be sent to the backend.

Thats fine.

Of course, this behaviour doesn't show up on a fast PC running the server on localhost :-)

Aaaah... now I know why with at 1600 (4pm) that redraw grew faster ... most people left the office, so the WAN was more responsive :) 
 

:-)

 

Regards, Dave .