[fdo-users] big oracle describe schema performance boost
Haris Kurtagic
haris at sl-king.com
Mon Aug 25 07:34:25 EDT 2008
Hi Zac,
One of connection properties of King.Oracle is also Oracle Schema, so if
you have all your geometry tables of interest in one Oracle Schema than
you can use that parameter.
I think that automatically creating FDO Schema and Class name from
Oracle schema/table/column is not straight forward .
For example in case you mentioned in Oracle table Region there could be
more than one geometry column.
Also there could be different Region tables in different Oracle Schemas.
King.Oracle added one table in which you can override names FDO
Schema.Class names created by provider.
One of things I was considering to add is to allow that this naming
rules can be written in local xml configuration file. One of advantages
would be that it is not necessary to add table to Oracle.
I think that bigger problem than that query itself is that for every
geometry table provider runs 2 more SQL statements.
In that case big improvements for MapGuide will be when MapGuide will
request FDO schema only for classes he needs to know about.
I will check sequence you mentioned and thank you for your analyses.
Haris
-----Original Message-----
From: fdo-users-bounces at lists.osgeo.org
[mailto:fdo-users-bounces at lists.osgeo.org] On Behalf Of Zac Spitzer
Sent: Monday, August 25, 2008 11:16 AM
To: FDO Users Mail List
Subject: Re: [fdo-users] big oracle describe schema performance boost
oops, i forgot about them being system tables.. sorry
in regards to having tables/views in different schema, isn't that what
fdo schema's aren't for?
ie
ZAC:REGION
rather than
KingOra:ZAC~REGION~GEOMETRY
if that was the case then, if the fdo schema is the current user, use
the faster USER_ approach,
otherwise fall back on the slower ALL_ views for when the user
explicity asks for something
which isn't in the default schema.
The performance gets worse and worse depending on the number of
objects in the oracle database
The following is a solution for the sequence problem
decode(s.sequence_owner,a.owner,s.sequence_name,null) sequence_name,
z
On Sat, Aug 23, 2008 at 12:36 AM, Barbara Zoladek
<barbara.zoladek at autodesk.com> wrote:
>
> Hi,
>
> Using USER_* views is possible only if the connected user and the
schema are the same. ALTER SESSION SET CURRENT_SCHEMA sets the current
schema so you don't need to qualify the objects with the schema name,
but it does not change the session user. Another reason for using ALL_*
views rather than USER_* is that you may have tables/views in different
schema rather than in one.
> USER_* views are based on the same objects as ALL_* views, the only
difference is the USER_* views have additional where clause 'owner=...'.
>
> Thanks,
> Barbara.
>
> -----Original Message-----
> From: fdo-users-bounces at lists.osgeo.org
[mailto:fdo-users-bounces at lists.osgeo.org] On Behalf Of Zac Spitzer
> Sent: Thursday, August 21, 2008 5:56 PM
> To: FDO Users Mail List
> Subject: [fdo-users] big oracle describe schema performance boost
>
> this is the query being used at the moment for an oracle describe
schema,
> (i did rewrite it without the where clause )
>
> SELECT a.owner, a.table_name, a.column_name, a.srid, a.diminfo,
b.cs_name,
> b.wktext, c.index_name, d.sdo_layer_gtype, s.sequence_name,
> d.sdo_root_mbr, NULL o1, NULL o2, NULL o3, NULL o4, NULL o5,
NULL o6,
> NULL o7, NULL o8, NULL o9, NULL o10, NULL o111, NULL o12
> FROM all_tab_columns t
> INNER JOIN all_sdo_geom_metadata a
> on t.owner = a.owner
> AND t.table_name = a.table_name
> AND t.column_name = a.column_name
> LEFT JOIN MDSYS.cs_srs b
> ON a.srid = b.srid
> LEFT JOIN all_sdo_index_info c
> ON a.owner = c.table_owner
> AND a.table_name = c.table_name
> LEFT JOIN all_sdo_index_metadata d
> ON c.sdo_index_owner =
d.sdo_index_owner
> AND c.index_name =
d.sdo_index_name
> LEFT JOIN all_sequences s
> ON s.sequence_name = CONCAT
(a.table_name, '_FDOSEQ')
> ORDER BY a.owner, a.table_name
>
> it's pretty slow because of the use of the all tables, i think there
> is a bug in there as well with
> the sequence join, it will match on duplicate table names in other
> schemas, but the performance
> goes to hell if you add the s.sequence_owner=t.owner crtieria
>
> if we just use the user views, that problem disappears
>
> SELECT a.table_name, a.column_name, a.srid, a.diminfo, b.cs_name,
> b.wktext, c.index_name, d.sdo_layer_gtype, s.sequence_name,
> d.sdo_root_mbr, NULL o1, NULL o2, NULL o3, NULL o4, NULL o5,
NULL o6,
> NULL o7, NULL o8, NULL o9, NULL o10, NULL o111, NULL o12
> FROM user_tab_columns t
> INNER JOIN user_sdo_geom_metadata a
> on t.table_name = a.table_name
> AND t.column_name = a.column_name
> LEFT JOIN MDSYS.cs_srs b
> ON a.srid = b.srid
> LEFT JOIN user_sdo_index_info c
> on a.table_name = c.table_name
> LEFT JOIN user_sdo_index_metadata d
> on c.index_name =
d.sdo_index_name
> LEFT JOIN user_sequences s
> ON s.sequence_name = CONCAT
(a.table_name, '_FDOSEQ')
> ORDER BY a.table_name
>
>
> the performance improvement and load reduction is quite dramatic, the
> difference is that user_tab_columns
> lists the objects owner by the users, whereas, the all_tab_columns
> lists all accessible tables
>
> when using these tables, a ALTER SESSION SET
> CURRENT_SCHEMA='%kingoracle.oracleschema%'
> would be required at the start of the session if you use a different
> username than the specified oracleschema
>
> small schema
> q_user_schema (Datasource=gis, Time=16ms, Records=4)
> q_all_schema (Datasource=gis, Time=1750ms, Records=4)
>
> big schema
> q_user_schema (Datasource=gis, Time=234ms, Records=146)
> q_all_schema (Datasource=gis, Time=1531ms, Records=146)
>
> z
>
>
>
>
>
> --
> Zac Spitzer -
> http://zacster.blogspot.com (My Blog)
> +61 405 847 168
> _______________________________________________
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--
Zac Spitzer -
http://zacster.blogspot.com (My Blog)
+61 405 847 168
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