I have been trying to chase down the same SQL being submitted against the same 10.2.0.4 Solaris database from different query tools used in our organization. I have been striking out when trying to match up by SQL ID. I connected with 4 different tools (and SQLPLUS on 2 platforms) and submitted the following 4 lines of SQL: SELECT * FROM EMP, DEPT WHERE EMP.DEPTNO=DEPT.DEPTNO The whitespace doesn't show in this format but the SQL was constructed with no spaces after the end of lines 1 and 4 and a single space character after the EMP and DEPT lines. In each tool I tried to execute with a ; or / at the end of the statement and luckily got the same SQL_ID out of each so at least that syntax difference I can ignore. Apologies to anyone reading without a fixed font: Tool SQL_ID v$sql.sql_fulltext observation: SQL Developer 3.0.02 on Win32 01xkza6wk1syd Looks same as input including whitespace SQLPLUS 10.2.0.4.0 Solaris 3jt52v806qzu6 Different - Trailing spaces removed from each line SQLPLUS 10.2.0.1.0 Win32 3jt52v806qzu6 Different - Trailing spaces removed from each line PL/SQL Developer 8.0.4.1514 Win32 54vxryr83c1pw Looks same as input including whitespace, OPTIMIZER_ENV_HASH_VALUE does differ from other runs Toad 9.6.11 Win32 gc3kk1r8ydrgw Different - Looks as if single space character was added to the end of last line Full details from v$sql for these 4 unique SQL_IDs available here: http://ba6.us/content/2011-07-21-SQL_ID_ClientTest.html I would revert to trying to match on SQL_TEXT field but even there I am seeing some white space differences which trip me up when I want to make sure I am matching the same exact text. So looking at sql_fulltext I did notice some whitespace differences between SQLPLUS and Toad - so that explains the different SQL_ID there. But I can't detect any differences between SQL Developer and PL/SQL Developer. Am I going crazy or is this each tool submitting the statement different enough that it causes a change in SQL ID? -Dave -- Dave Mann www.brainio.us www.ba6.us - Database Stuff - http://www.ba6.us/rss.xml -- //www.freelists.org/webpage/oracle-l