![]() ![]() The create index statement above at the same time, under the covers, creates an associated table and trigger. The ctxsys.ctxcat index is fully transaction aware by default (unlike some other full text index types), even detecting changes in current session prior to commit. SELECT * FROM t1 WHERE CATSEARCH ( t1.text, 'smith', NULL ) > 0įor most applications, that word boundary behaviour would be acceptable or even desirable. ![]() INSERT INTO t1 ( text ) VALUES ( '4 CustomerSmithInfo' ) INSERT INTO t1 ( text ) VALUES ( '3 Customer-Smith-info' ) INSERT INTO t1 ( text ) VALUES ( '2 Customer smith info' ) Word boundaries are enforced with catgroup, so the below catsearch returns only rows 1-3, misses out row 4 even though that would be caught by “LIKE ‘%smith%'” type conditions: INSERT INTO t1 ( text ) VALUES ( '1 Customer Smith info' ) A catsearch of ‘within group’ is the same as “grep -i within | grep -i group”, rather than “grep -i ‘within group'”. Once that index is created, the catsearch query runs without error, and runs very fast.Ĭatsearch is case insensitive, but it does behave differently from “LIKE ‘%term%'” in that it searches for occurrences of words rather than text strings. SELECT * FROM t1 WHERE CATSEARCH ( t1.text, 'within group', NULL ) > 0 Until a full text index is created on the column: CREATE TABLE t1 AS SELECT * FROM dba_source ĬREATE INDEX i1 ON t1 ( t1.text ) INDEXTYPE IS CTXSYS.CTXCAT That last command will fail with: ORA-20000: Oracle Text error: DRG-10599: column is not indexed Oracle’s fast indexed equivalent of grep is catsearch: SELECT * FROM dba_source s WHERE CATSEARCH ( s.text, 'within group', NULL ) > 0 But for even medium sized tables, you really want a fast indexed query, which the “LIKE ‘%” syntax ordinarily rules out. That works fast enough for querying dba_source, which is a small dataset. ![]() The equivalent of the grep command in oracle is like: SELECT * FROM dba_source s WHERE LOWER ( s.text ) LIKE '%within group%' Oracle Full Text simple example for like % grep wildcard ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |