[fdo-users] big oracle describe schema performance boost
Zac Spitzer
zac.spitzer at gmail.com
Mon Aug 25 09:58:15 EDT 2008
On Mon, Aug 25, 2008 at 11:26 PM, Haris Kurtagic <haris at sl-king.com> wrote:
> Zac,
>
> I have quickly read that discussion, I haven't see it before.
>
> I will try to explain myself with example:
> In case there are two oracle schemas "Ora1" and "Ora2" and two geometry
> tables "Region" (one in each oracle schema) and each table has two
> geometry columns "Geom1" and "Geom2".
> So in Oracle we have 4 geometries which are accessed as:
> "Ora1.Region.Geom1", "Ora1.Region.Geom2", "Ora2.Region.Geom1",
> "Ora2.Region.Geom2"
>
> So provider needs to create 4 different FDO classes and obviously FDO
> class name can't be just oracle table name "Region".
isn't FDO primarily a table approach, in studio there is always a drop down to
select which geometry column to use.. why does a table make it two
logical feature
classes when they are just one?
Is their an assumed primary geometry on a featureclass ?
a single indexed geometry per table is by far the most common use out there
> Provider keeps physical mapping to real oracle schema.table ( it is not
> parsed from name ).
i don't understand, not parsing implies not using the class name?
>
> Oracle username in connection doesn't mean that we access only that
> Oracle schema. One user can have access to several Oracle schemas.
But king oracle only ever exposes everything as single schema, that
being kingOra,
which makes portability difficult between datasources.
shouldn't getschema's return a list of all the schemas available to
the current user in oracle?
Looking at the Mapguide API i can see why it's implemented the way it is
virtual MgFeatureReader SelectFeatures(MgResourceIdentifier resource,
string className, MgFeatureQueryOptions options);
shouldn't there be a schemaName in there, that's why you used the full
approach ?
> As mentioned in discussion it can be problem to keep same schema.class
> name across provider.
> For example with SHP provider schema is always SHP so it is problem when
> creating application to work over all providers with preset schema.class
> names.
but then the shape provider could just ignore schema altogether
I have lots of sdf's which have kingora: schemas, it's a good way to
be able simply swap
between oracle and sdf.
>
> With King.Oracle provider only way to get same FDO class name as you
> used in create class is to have extra table (KingFdoClass). I think that
> would solve Bruno problem with class names for King.Oracle.
>
> 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 2:06 PM
> To: FDO Users Mail List
> Subject: Re: [fdo-users] big oracle describe schema performance boost
>
> On Mon, Aug 25, 2008 at 9:34 PM, Haris Kurtagic <haris at sl-king.com>
> wrote:
>>
>> I think that automatically creating FDO Schema and Class name from
>> Oracle schema/table/column is not straight forward .
>
> I can't see why at least the schema part is not done fdo style
>
> ZAC:REGION~GEOMETRY
>
> but why is the geometry column needed in the first place?
>
> this was previously discussed here
> http://www.nabble.com/Is-there-a-Feature-class-naming-convention-td15021
> 175.html
> http://trac.osgeo.org/fdo/ticket/374
>
> z
>
>
>> 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
>>> _______________________________________________
>>> fdo-users mailing list
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>>
>>
>>
>> --
>> Zac Spitzer -
>> http://zacster.blogspot.com (My Blog)
>> +61 405 847 168
>> _______________________________________________
>> fdo-users mailing list
>> fdo-users at lists.osgeo.org
>> http://lists.osgeo.org/mailman/listinfo/fdo-users
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>
>
>
> --
> Zac Spitzer -
> http://zacster.blogspot.com (My Blog)
> +61 405 847 168
> _______________________________________________
> fdo-users mailing list
> fdo-users at lists.osgeo.org
> http://lists.osgeo.org/mailman/listinfo/fdo-users
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--
Zac Spitzer -
http://zacster.blogspot.com (My Blog)
+61 405 847 168
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