I guess note number one about MyISAM to Innodb migration is warning what Innodb is very slow in COUNT(*) queries. The part which I often however see omitted is fact it only applies to COUNT(*) queries without WHERE clause.
So if you have query like SELECT COUNT(*) FROM USER It will be […]
I had found pile of MySQL and PostgreSQL benchmarks on various platforms which I have not seen before. Very interesting reading.
It does not share too much information about how MySQL or PostgreSQL was configured or about queries. Furthermore MySQL and PostgreSQL has a bit different implementations (ie SubQueries avoided for MySQL) so do […]
One may have notice we were not blogging too much recently, this is because we were quite busy, mainly building BoardReader.com – Search Engine which indexes tens of thousands of forums from all over the world. This project was built by us as consulting project so too bad we do not […]
Read moreIn the past life was easy in MySQL. Both CHAR and VARCHAR types meant the same, only being difference in the sense of fixed or dynamic row length used. Trailing spaces were removed in both cases.
With MySQL 5.0 however things changed so now VARCHAR keeps trailing spaces while CHAR columns do not any […]
I already wrote in the blog as well mentioned in presentation there is often a choice you have to make between having prefix index – which can be significantly smaller in size and having index being covering index, which means query can be executed using only data from the index without reading the row […]
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