>From the MySQL page http://dev.mysql.com/doc/refman/5.0/en/create-index.html it says:
BLOB and TEXT columns also can be indexed, but a prefix length must be given. Prefix lengths are given in characters for non-binary string types and in bytes for binary string types. That is, index entries consist of the first length characters of each column value for CHAR, VARCHAR, and TEXT columns, and the first length bytes of each column value for BINARY, VARBINARY, and BLOB columns. ### So I'm not sure if it is really useful to index these columns. Is there ever a lookup done on object contents? I also found this item: http://www.idevelopment.info/data/Oracle/DBA_tips/LOBs/LOBS_2.shtml which show how to create a table with a LOB (large object either BLOB or CLOB) but it looks like you have to specify a TABLESPACE to hold the BLOB/CLOB index. Does anyone have a sense of whether this is worth the effort to index XWiki CLOB's ? CREATE TABLE test_lobtable ( id NUMBER , xml_file CLOB , image BLOB , log_file BFILE ) LOB (xml_file) STORE AS xml_file_lob_seg ( TABLESPACE lob_data CHUNK 4096 CACHE STORAGE (MINEXTENTS 2) INDEX xml_file_lob_idx ( TABLESPACE lob_index STORAGE (MAXEXTENTS UNLIMITED) ) ) ---snip--- Here is Hibernate reference to using Oracle CLOB : http://www.hibernate.org/56.html but it mentions nothing about indexes. -- View this message in context: http://www.nabble.com/Oracle-Database-Index-tp16945142p16974580.html Sent from the XWiki- Dev mailing list archive at Nabble.com. _______________________________________________ devs mailing list [email protected] http://lists.xwiki.org/mailman/listinfo/devs
