I hit this issue by accident, developers wanted to disable inserts to child table so they could perform some one-time maintenance operation, and this maintenance only affected one rown from the parent table (and all it’s children). I started wondering if there is any smaller level impact solution possible than taking a shared read lock on child table.
Database version: 126.96.36.199, but the same behaviour was also present in 188.8.131.52.
When it comes to schema design, one of the more common issues I see for INNODB tables is in the selection of a primary key, or an absence of a primary key entirely. Today I would like to illustrate some of the best practices when it comes to selecting a primary key for your consideration as you design new tables for your schema, or modify existing ones.
Let’s start by reviewing how the table structure works in INNODB.
Dbvisit was invited to participate in a very unique roadshow in Switzerland this week. Our Swiss partner dbi services hosted this event across two cities in Switzerland. Three different companies each presented their tool regarding ‘Oracle Replication’ including Oracle GoldenGate, Dbvisit Replicate and Attunity. I flew into Geneva and then took the train to Lausanne.…
In the previous instalment (link when it’s posted) in this series we introduced Change Data Capture as an “engine” which can power the publication of a continuous stream of changes from an RDBMS – delivering both the change data and metadata (information about the changes) to boot. In a database context then this would be…
I have seen it stated many times that MySQL redo log files or ib_logfiles, are used in a circular fashion – even the
href="https://dev.mysql.com/doc/refman/5.7/en/innodb-redo-log.html">manual says so. However during one of my observations, I saw the following behaviour in MySQL 5.6:
I occasionally get questions from customers and colleagues about performance expectations for the Oracle Database procedure called calibrate_io on XtremIO storage. This procedure must be executed in order to update the data dictionary. I assert, however, that it shouldn’t be used to measure platform suitability for Oracle Database physical I/O. The main reason I say this is because calibrate_io is a black box, as it were.