Article ID:	42983
Software:	ArcSDE 10.1, 10.2, 10.2.1, 10.2.2 ArcGIS for Desktop Advanced 10.1, 10.2, 10.2.1, 10.2.2, 10.1 SP1, 10.3 ArcGIS for Desktop Standard 10.1, 10.2, 10.2.1, 10.2.2, 10.1 SP1, 10.3 ArcGIS for Desktop Basic 10.1, 10.2, 10.2.1, 10.2.2, 10.1 SP1, 10.3
Platforms:	N/A

Question

In Oracle, why does it take a long time to build statistics on large ST_GEOMETRY data?在Oracle資料庫中，為什麼對大資料量（ST_Geometry)建立統計資訊會消耗非常長的時間？

Answer

Attempting to use the ArcCatalog 'Analyze...' command or gathering table statistics in SQL*Plus for a feature class using ST_GEOMETRY in Oracle can take a very long time to complete. 不管是使用ArcCatalog的分析功能（Analyze）或者是使用Oracle提供的統計資訊的儲存過程dbms_stats.gather_table_stats都會消耗非常長的時間

Example

SQL*Plus example:
 

set timing on
exec dbms_stats.gather_table_stats('BEN','ROADS_1M')

Results :
PL/SQL procedure successfully completed.

43:36:39.79

SQL to identify the poorly performing query :

SELECT se.sid,se.username,sa.sql_text 
FROM v$session se, v$sqlarea sa 
WHERE se.sql_address=sa.address 
AND se.sql_hash_value=sa.hash_value;

Poorly Performing Query :
 


SELECT /*+ no_parallel(b) no_parallel_index(b) 
dbms_stats cursor_sharing_exact use_weak_name_resl 
dynamic_sampling(0) no_monitoring 
*/ dbms_rowid.rowid_block_number(b.rowid) 
FROM 
(SELECT s.sp_id, s.gx, s.gy, row_number() 
OVER
( Partition BY s.sp_id ORDER BY s.gx, s.gy) rncol 
FROM BEN.S57_IDX$ s) sp, BEN.ROADS_1M b 
WHERE rncol = 1 AND b.rowid = sp.sp_id 
ORDER BY sp.gx, sp.gy, sp.sp_id

This behavior has been identified to occur in versions of Oracle prior to 11.2.0.4.0. Esri recommends using Oracle versions 11.2.0.4.0 or above, which use a better execution plan than previous Oracle releases, and this in turn improves the statistics building process. 

這種情況會在Oracle 11.2.0.4以前的版本發生，Esri建議如果需要解決該問題，升級你的Oracle版本11.2.0.4或者以上，在該環境下可以提高相關的執行效率.

If this behavior is encountered, consider upgrading the Oracle instance to a minimum version of 11.2.0.4.0 or 12.1.0.1.0.

如果有使用者碰到相關問題，建議升級Oracle版本11.2.0.4或者12.1.0.1

Bug NIM-084365

Nimbus ID	NIM084365
Submitted	Sep 4, 2012 11:20 AM
Severity	Medium
Applies To	ArcGIS
Version Found	10.0
Prog Language	N/A
Server Platform	All
Client Platform	All Windows
Database	Oracle
Locale	N/A
Status	Declined
Version Fixed	N/A
SP Fixed	N/A

Synopsis

Gathering table statistics using Oracle DBMS_STATS.GATHER_TABLE_STATS generates high CPU usage and runs very slow for large SDE layers with ST_GEOMETRY data type.

Additional Status Information

N/A

Alternate Solution

N/A

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