This is a read-only copy of the MariaDB Knowledgebase generated on 2024-11-24. For the latest, interactive version please visit https://mariadb.com/kb/.

Optimizing String and Character Fields

Comparing String Columns

When values from different columns are compared, the comparison runs more quickly when the columns are of the same character set and collation. If they are different, the strings need to be converted while the query runs. So, where possible, declare string columns using the same character set and collation when you may need to compare them.

VARCHAR vs BLOB

ORDER BY and GROUP BY clauses can generate temporary tables in memory (see MEMORY Storage Engine) if the original table doesn't contain any BLOB fields. If a column is less than 8KB, you can make use of a Binary VARCHAR rather than a BLOB.

Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party.