Oracle

impdp content=metadata_only locks the stats

By Franck Pachot . With Oracle you can learn something every day. Today, preparing a migration to 12.2, I found all tables had locked statistics. I learned that it is the expected behavior since 10.2 when importing metadata_only including statistics,(…)

12c dbms_stats.gather_table_stats on GTT do not commit

By Franck Pachot . In my UKOUG OracleScene article on 12c online statistics and GTT I mentioned the following: A final note about those 12c changes in statistics gathering on GTT. In 11g the dbms_stats did(…)

When PDB name conflicts with CDB name

By Franck Pachot . Going to multitenant architecture is not a big change. The administration things (DBA, monitoring, backups) connect to the CDB and the application things connect to the PDB. Without the multitenant option, it is still recommended to(…)

Postgres vs. Oracle access paths XI – Sample Scan

By Franck Pachot . I was going to end this series with the previous post because the last access path available in Postgres is a bit special: a Seq Scan that returns only a sample of(…)

Postgres vs. Oracle access paths X – Update

By Franck Pachot . In the previous post we have seen the cheapest way to get one row, reading only one block from its physical location. But that's the optimal case where the row has not(…)

Postgres vs. Oracle access paths IX – Tid Scan

By Franck Pachot . In the previous post we have seen how Postgres and Oracle finds the table row from the index entry. It uses the TID / ROWID. I’ll focus on this access path(…)

Improving Statspack Experience

By Franck Pachot . I've published a few month ago an article in the UKOUG OracleScene magazine on Improving Statspack Experience: quick setup script, changing settings, filling Idle Events,etc. In the article, I used dbms_job to(…)

Bequeath connect to PDB: set container in logon trigger?

By Franck Pachot . There are little changes when you go to multitenant architecture and one of them is that you must connect with a service name. You cannot connect directly to a PDB with a beaqueath (aka local) connection.

Postgres vs. Oracle access paths VIII – Index Scan and Filter

By Franck Pachot . In the previous post we have seen a nice optimization to lower the consequences of bad correlation between the index and the table physical order: a bitmap, which may include false positives(…)

ODA X6 2S 2M 2L HA: Small Medium Large and High Availability

By Franck Pachot . There are 4 models of Oracle Database Appliance with the new ODA X6 which is for the moment the latest ODA hardware version. One is similar to the(…)