About Lesson
The following table describes various hard limits of PostgreSQL. However, practical limits, such as performance limitations or available disk space may apply before absolute hard limits are reached.
Table K.1. PostgreSQL Limitations
| Item | Upper Limit | Comment |
|---|---|---|
| database size | unlimited | |
| number of databases | 4,294,950,911 | |
| relations per database | 1,431,650,303 | |
| relation size | 32 TB | with the default BLCKSZ of 8192 bytes |
| rows per table | limited by the number of tuples that can fit onto 4,294,967,295 pages | |
| columns per table | 1600 | further limited by tuple size fitting on a single page; see note below |
| field size | 1 GB | |
| identifier length | 63 bytes | can be increased by recompiling PostgreSQL |
| indexes per table | unlimited | constrained by maximum relations per database |
| columns per index | 32 | can be increased by recompiling PostgreSQL |
| partition keys | 32 | can be increased by recompiling PostgreSQL |