INSERT creates new rows in a table. Can insert rows from values or queries. Column names can be listed in any order. Default values are used for missing columns. Automatic type conversion is attempted
Integer types store whole numbers with various ranges. Integer is most common choice for balance between range and performance. Smallint used when disk space is limited. Bigint used when integer range is insufficient
Date/time operators (+, -, *, /) work with dates, timestamps, and intervals. Dates and timestamps are comparable, while times and intervals are limited. Timestamp comparisons with time zone are rotated to UTC
Functions convert various data types to formatted strings. Formatting follows common convention: value first, template second. Functions include to_char for timestamps, to_date for dates, to_number for numbers
ALTER TABLE modifies existing table definitions. ACCESS EXCLUSIVE lock required unless explicitly specified. Multiple subcommands can be combined for bulk changes
UPDATE modifies values in rows satisfying specified conditions. Only modified columns need explicit specification in SET clause. Can modify tables using sub-selects or FROM clause. Optional RETURNING clause computes values based on updated rows