Oracle Index compression for range scan on file names

A new blog post on the Databases at CERN blog about tables storing long file names in a table, with full path, and index range scan on a…

Oracle Index compression for range scan on file names

A new blog post on the Databases at CERN blog about tables storing long file names in a table, with full path, and index range scan on a prefixed pattern: https://db-blog.web.cern.ch/blog/franck-pachot/2018-11-oracle-index-compression-range-scan-file-names

COMPRESS ADVANCED LOW

The 12cR1 advanced index compression does not help here as all values are unique. Only partial prefix is redundant.

COMPRESS ADVANCED HIGH

The advanced algorithm ‘high’ introduced in 12cR2 can reduce better. But there’s no magic. Redundancy should be addressed at design. Full test:

Oracle Index compression for range scan on file names
I read 131 buffers to get my 15625 file names from the non-compressed index. Nearly the same, 128 buffers, for the…db-blog.web.cern.ch