The task of the planner/optimizer is to create an optimal execution plan. A given SQL query (and hence, a query tree) can be actually executed in a

PostgreSQL enforces SQL uniqueness constraints using unique indexes, which are indexes that disallow multiple entries

The core PostgreSQL distribution includes the SP-GiST operator classes shown in Table 62-1.

BRIN stands for Block Range Index. BRIN is designed for handling very large tables in which certain columns

The executor takes the plan created by the planner/optimizer and recursively processes it to extract the required set of rows. This is essentially

The PostgreSQL source distribution includes several examples of index methods implemented using GiST. The

Index access methods must handle concurrent updates of the index by multiple processes. The core PostgreSQL system obtains

In an index scan, the index access method is responsible for regurgitating the TIDs of all the tuples it has been told about that match the scan keys

The examples shown below use tables in the PostgreSQL regression test database. The outputs shown are taken from version 8.3. The behavior

Traditionally, implementing a new index access method meant a lot of difficult work. It was necessary to understand the inner workings of the database, such as the lock manager