Plate III · Filed under
Indexing
Indexing
2 entries
- 001
PostgreSQL composite indexes: which column goes first
A multicolumn B-tree sorts by its first column, then its second. Why (a, b) and (b, a) are different indexes, and the rule that decides the order.
PostgreSQLDatabasesIndexingPerformance - 002
UUID primary keys and write amplification in PostgreSQL
A UUIDv4 primary key scatters every insert across the B-tree, turning one logical write into several physical ones. The mechanism, and when it matters.
PostgreSQLDatabasesUUIDPerformance