[postgis-devel] GiST estimate and index_extent()

[Mark Cave-Ayland]

Hi strk,

> -----Original Message-----
> From: strk at refractions.net [mailto:strk at refractions.net] 
> Sent: 13 January 2005 11:08
> To: Mark Cave-Ayland
> Cc: 'PostGIS Development Discussion'
> Subject: Re: [postgis-devel] GiST estimate and index_extent()
> 
> 
> Mark,
> Paul actually did not express his preference about this, and 
> actually I'm not convinced as well... I'm not sure 2 days 
> will be enough, not for the implementation but for the 
> decisions reguarding backward-compatibility. If we find a 
> clean solution today I think that would be ok.
> 
> We currently have a fix_geometry_columns() which fixes 
> f_table_schema, attrelid and varattnum. The function is 
> automatically invoked by AddGeometryColumn() and 
> update_geometry_stats().
> 
> What we could do is drop the automatic invokation and improve 
> it to drop attrelid, varattnum and stats if present for 
> PG>=800 and to change stats into a stakind1 smalint / 
> stanumbers1 float[] for PG<800 if stats is present. Note that 
> in this case the HISTOGRAM2D type would be pretty useless, so 
> we could drop it as well.

Note that we don't need to convert old stats into float[] because once a
database has been restored the user would have to VACUUM ANALYZE anyway
which would automatically generate a new histogram. And yes, we could drop
the HISTOGRAM2D type.

> About TODOs, running regression tests I found that lwgparser 
> does not check polygon validity as did HWGEOM do. Maybe that 
> should be added, but I guess could wait for 1.0 or RC2.
> 
> Comments ?

If this could cause us to allow invalid geometries into PostGIS then my call
would be to fix it so we can help protect users from themselves! I don't
think this will be too difficult for anyone with experience with
lexers/parsers....


Kind regards,

Mark.

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