Importing statistics using datapump

Question

When importing production data into my test databases (schema imports) I want ot import the production statistics for the imported schemas, then lock them, so hopefully all testing will be done using the same explain plans.
When using expdp on production I do not specify eny EXCLUDE objects and when I impdp into my test DB it imported most of the stats but for 3 tables and all their indexes it regathererd the stats.
Any ideas which it recalculated stats for just 3 tables (+ indexes) and how I can avoid this.
The schemas I import into are droped and recreated prior to the import.

Answer 1

Hi,
You don't mention what version you are running. The following works on 10.2 and newer. The reason stats are regathered is due to some type of background process that regathers stars on tables if stats exists and if the database is idle. (Or at least that is what I seem to remember reading.) I don't know all of the conditions, but that is what is happening. If you don't create stats, then they are not regathered.
To verify that you don't have the lock code from Data Pump, you could run the impdp command and add:
content=metadata_only include=statistics sqlfile=stats.sql
Then edit the stats.sql file to see if there are calls to dbms_stats.lock
If you have this support, you should see
dbms_stats.lock_table_stats for each table and
dbms_stats.lock_index_stats for each index
Dean
p.s. Here ia a section of my sqlfile for the HR schema
DECLARE
c varchar2(60);
nv varchar2(1);
df varchar2(21) := 'YYYY-MM-DD:HH24:MI:SS';
s varchar2(60) := 'HR';
t varchar2(60) := 'REGIONS';
p varchar2(1);
sp varchar2(1);
stmt varchar2(300) := 'INSERT INTO "SYS"."IMPDP_STATS" (type,version,c1,c2,c3,c4,c5,n1,n2,n3,n4,n5,n6,n7,n8,n9,n10,n11,d1,r1,r2,ch1,flags) VALUES (''C'',5,:1,:2,:3,:4,:5,:6,:7,:8,:9,:10,:11,:12,:13,:14,:15,:16,:17,:18,:19,:20,:21)';
BEGIN
DELETE FROM "SYS"."IMPDP_STATS";
INSERT INTO "SYS"."IMPDP_STATS" (type,version,flags,c1,c2,c3,c5,n1,n2,n3,n4,n10,n11,n12,d1) VALUES ('T',5,2,t,p,sp,s,
4,1,14,4,NULL,NULL,NULL,
TO_DATE('2009-09-16 21:40:06',df));
c := 'REGION_ID';
EXECUTE IMMEDIATE stmt USING t,p,sp,c,s,
4,.25,4,4,0,1,4,3,nv,nv,nv,
TO_DATE('2009-09-16 21:40:06',df),'C102','C105',nv,2;
c := 'REGION_NAME';
EXECUTE IMMEDIATE stmt USING t,p,sp,c,s,
4,.25,4,4,0,3.39718115904673E+35,4.01944465011359E+35,11,nv,nv,nv,
TO_DATE('2009-09-16 21:40:06',df),'416D657269636173','4D6964646C65204561737420616E6420416672696361',nv,2;
DBMS_STATS.IMPORT_TABLE_STATS('"HR"','"REGIONS"',NULL,'"IMPDP_STATS"',NULL,NULL,'"SYS"');
DELETE FROM "SYS"."IMPDP_STATS";
END;
BEGIN
DBMS_STATS.LOCK_TABLE_STATS('"HR"','"REGIONS"','ALL');
END;
/