Note: Not all functions are supported by all builds. It depends on your libpq (The PostgreSQL C client library) version and how libpq is compiled. If PHP PostgreSQL extensions are missing, then it is because your libpq version does not support them.
Note: Most PostgreSQL functions accept connection as the first optional parameter. If it is not provided, the last opened connection is used. If it doesn't exist, functions return FALSE.
Note: PostgreSQL automatically folds all identifiers (e.g. table/column names) to lower-case values at object creation time and at query time. To force the use of mixed or upper case identifiers, you must escape the identifier using double quotes ("").
Note: PostgreSQL does not have special commands for fetching database schema information (eg. all the tables in the current database). Instead, there is a standard schema named information_schema in PostgreSQL 7.4 and above containing system views with all the necessary information, in an easily queryable form. See the » PostgreSQL Documentation for full details.