資料類型（Data Type）
官網：https://www.postgresql.org/docs/10/static/datatype.html
數字類型（Numeric Types）
| Name | Storage Size | Description | Range |
|---|---|---|---|
| smallint | 2 bytes | small-range integer | -32768 to +32767 |
| integer | 4 bytes | typical choice for integer | -2147483648 to +2147483647 |
| bigint | 8 bytes | large-range integer | -9223372036854775808 to +9223372036854775807 |
| decimal | variable | user-specified precision, exact | up to 131072 digits before the decimal point; up to 16383 digits after the decimal point |
| numeric | variable | user-specified precision, exact | up to 131072 digits before the decimal point; up to 16383 digits after the decimal point |
| real | 4 bytes | variable-precision, inexact | 6 decimal digits precision |
| double precision | 8 bytes | variable-precision, inexact | 15 decimal digits precision |
| smallserial | 2 bytes | small autoincrementing integer | 1 to 32767 |
| serial | 4 bytes | autoincrementing integer | 1 to 2147483647 |
| bigserial | 8 bytes | large autoincrementing integer | 1 to 9223372036854775807 |
貨幣類型（Monetary Types）
| Name | Storage Size | Description | Range |
|---|---|---|---|
| money | 8 bytes | currency amount | -92233720368547758.08 to +92233720368547758.07 |
字元類型（Character Types）
| Name | Description |
|---|---|
| character varying(n), varchar(n) | variable-length with limit |
| character(n), char(n) | fixed-length, blank padded |
| text | variable unlimited length |
二進制資料類別（Binary Data Types）
| Name | Storage Size | Description |
|---|---|---|
| bytea | 1 or 4 bytes plus the actual binary string | variable-length binary string |
日期時間類別（Date/Time Types）
| Name | Storage Size | Description | Low Value | High Value | Resolution |
|---|---|---|---|---|---|
| timestamp [ (p) ] [ without time zone ] | 8 bytes | both date and time (no time zone) | 4713 BC | 294276 AD | 1 ms |
| timestamp [ (p) ] with time zone | 8 bytes | both date and time, with time zone | 4713 BC | 294276 AD | 1 ms |
| date | 4 bytes | date (no time of day) | 4713 BC | 5874897 AD | 1 day |
| time [ (p) ] [ without time zone ] | 8 bytes | time of day (no date) | 00:00:00 | 24:00:00 | 1 ms |
| time [ (p) ] with time zone | 12 bytes | time of day (no date), with time zone | 00:00:00+1459 | 24:00:00-1459 | 1 ms |
| interval [ fields ] [ (p) ] | 16 bytes | time interval | -178000000 years | 178000000 years | 1 ms |
布林類別（Boolean Types）
| Name | Storage Size | Description |
|---|---|---|
| boolean | 1 byte | state of true or false |
幾何類型（Geometric Types）
| Name | Storage Size | Description | Representation |
|---|---|---|---|
| point | 16 bytes | Point on a plane | (x,y) |
| line | 32 bytes | Infinite line | {A,B,C} |
| lseg | 32 bytes | Finite line segment | ((x1,y1),(x2,y2)) |
| box | 32 bytes | Rectangular box | ((x1,y1),(x2,y2)) |
| path | 16+16n bytes | Closed path (similar to polygon) | ((x1,y1),...) |
| path | 16+16n bytes | Open path | [(x1,y1),...] |
| polygon | 40+16n bytes | Polygon (similar to closed path) | ((x1,y1),...) |
| circle | 24 bytes | Circle | <(x,y),r> (center point and radius) |