Oracle

Variations on 1M rows insert (5): using ‘perf’

By Franck Pachot . In previous post I explained that I’ve observed a 2x CPU usage when running my insert test case in 11.2.0.4 vs. 11.2.0.2 I discussed that with @martinberx @OracleSK @TanelPoder @xtner @Ycolin @fritshoogland @lleturgez @LucaCanaliDB on(…)

Variations on 1M rows insert (4): IN MEMORY

By Franck Pachot . Oracle In-Memory option is for reporting. Oracle has chosen an hybrid approach: maintain the In-Memory Column Store in addition of the buffer cache. Dont’ forget our In-Memory event, but for the moment, let’s try(…)

Matching SQL Plan Directives and queries using it

By Franck Pachot . This is another blog post I’m writing while reviewing the presentation I’m doing next week forSOUG and next month for DOAG. You have SQL Plan Directives used by several queries that have same(…)

Matching SQL Plan Directives and extended stats

By Franck Pachot . This year is the year of migration to 12c. Each Oracle version had its CBO feature that make it challenging. The most famous was the bind variable peeking in 9iR2. Cardinality feedback in 11g also(…)

Variations on 1M rows insert (4): APPEND_VALUES

By Franck Pachot . In the first variation I did a bulk insert with the PL/SQL FORALL statement. A comment suggests to add the APPEND_VALUES hint that appeared in 11gR2. APPEND_VALUES hint does the same than APPEND but(…)

Rebuilt index on increasing values after deletes?

By Franck Pachot . Yesterday while giving our Oracle tuning workshop I discussed with the customer about a job they have that rebuilds indexes every Sunday. Except in very rare cases Oracle indexes are maintained so that free(…)

Variations on 1M rows insert (3): TimesTen

By Franck Pachot . In the previous blog post I measured how inserting 1 million rows takes 5 minutes instead of 45 seconds when we commit at each row inserted. In Oracle we can improve that down to(…)

Variations on 1M rows insert(2): commit write

By Franck Pachot . In the previous blog post I measured the time it takes to insert 1 million rows. About 45 seconds when done row-by-row which goes down to 7 seconds when inserted in bulk. In both(…)

Variations on 1M rows insert (1): bulk insert

By Franck Pachot . This blog is the first one of a series about inserting 1 million rows. Do you have an idea about the time it takes? The idea came from another project, about NoSQL databases, but I’ll(…)

A migration pitfall with ALL COLUMN SIZE AUTO

By Franck Pachot . When you migrate, you should be prepared to face some execution plan changing. That’s not new. But here I’ll show you a case where you have several bad execution plans because lot of histograms are(…)