Tag: database
InnoDB vs MyISAM
InnoDB is the default MySQL storage engine supporting transactions, foreign keys, and row-level locking — MyISAM is legacy with table-level locking and no transaction support.
2mo ago
database beginner
INSERT ... ON DUPLICATE KEY UPDATE PHP 5.1+
An atomic MySQL upsert — inserts a new row or updates the existing one if a unique key constraint would be violated.
2mo ago
database intermediate
Index Selectivity & Cardinality PHP 5.0+
High-cardinality columns (user IDs, emails) make effective indexes; low-cardinality columns (boolean, status with 3 values) rarely benefit from single-column indexes.
2mo ago
performance intermediate