By Franck Pachot . A covering index is an index that contains all the columns required by your query, so that you don’t have to do a TABLE ACCESS BY INDEX ROWID, which is the major cost of an index range scan. You don’t need any special feature to do that in Oracle. Just add the required columns at the…
In order to start index agents, you have several ways, depending on how you need to start them. 1. Use the documentum job dm_FTIndexAgentBoot. If you setup start_index_agents=T in the server.ini, the job will be called when the docbases are started. 2. Use the web interface: Login to http://server:9200/IndexAgent/ with docbase credentials and select “Start in normal mode” 3. Login…
By Mouhamadou Diaw A few time ago my colleague Daniel did a blog about POWA. In a nice article he shown how this tool can be used to monitor our PostgreSQL. In this present article I am going to show how this powerful tool can help by suggesting indexes which can optimize our queries. I am using postgeSQL 9.6 [root@pgservertools…
We had a strange behavior by a customer regarding the indexing queue. We used to have two IA configured and we uninstalled one. I figured out that we still had indexing queue requests for the old index agent while it was totally uninstalled. I checked the following objects to see if the agent was still configured somewhere: dm_fulltext_index, dm_ftengine_config, dm_ftindex_agent_config.…
By Franck Pachot . A common question is: how to know which indexes are not used, so that I can drop them. If you tried to use index monitoring you probably have seen the limits of it which make it difficult to use. It has been improved in 12.2 so let’s check if it helps to release the stress of…
A couple of weeks ago, I was charged to migrate an SQL Server datawarehouse environment to a more recent version of SQL Server (from 2005 to 2012 in my case). After discussing with my customer we decided to benefit from the nonclustered columnstore index feature to improve reporting queries performance directly executed against the concerned database. So the implementation was…
Did you miss aggregate pushdown capability shipped with columnstore index? Well, I remember the first time I heard about it is was when I read the very interesting blog post of Niko Neugebauer here with a very good covering of the topic (principle, advantages and limitations). So why to write a new blog post here? Well because since the last…
By Franck Pachot . Do you think that online operations are available only on Enterprise Edition? That changed in 12c, there is an operation that is online (without the need for the ONLINE keyword) and available in Standard Edition and a very important feature for performance tuning: invisible indexes. Example I’ll show it from the SCOTT schema where I’ve added…
