Postgres

SQL DB with:

  • Streaming replication

  • Schemas

  • User-defined objects like operators, data types, and functions

  • Nested transactions

  • Table inheritance

  • Partitioning

  • Several unusual data types, like Money, Geometry, IP addresses, JSON, and data ranges.

  • Can execute stored procedures in over a dozen programming languages, including Java, Perl, Python, Ruby, and C/C++.

Types

Character Types

Description

character varying(n), varchar(n)

variable-length with limit

character(n), char(n)

fixed-length, blank padded

text, varchar

variable unlimited length

If you do not specify the n integer for the varchar data type, it behaves like the text data type. The performance of the varchar (without n) and text are the same.

Psql

  • \du to see users installed

  • \list: lists all the databases in Postgres

  • \connect: connect to a specific database

  • \dt: list the tables in the currently connected database

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