The compiler supports the following SQL data types:

• BOOLEAN, or BOOL, represented as a Boolean value
• TINYINT, represented as an 8-bit signed integer using two's complement.
• SMALLINT, or INT2, represented as a 16-bit signed integer using two's complement.
• INTEGER, or INT, or SIGNED, or INT4, represented as a 32-bit signed integer, using two's complement
• BIGINT, or INT64, represented as a 64-bit signed integer, using two's complement
• DECIMAL(precision,scale), or DEC(precision, scale), or NUMERIC(precision, scale), or NUMBER(precision, scale), a high precision fixed-point type, with a precision (total number of decimal digits) and a scale (number of decimal digits after period). For example, 23.456 has a precision of 5 and a scale of 3. If scale is missing it is assumed to be 0.
• FLOAT, or FLOAT4, or FLOAT32, or REAL, an IEEE 32-bit floating point number
• DOUBLE, or FLOAT8, or FLOAT32, an IEEE 64-bit floating point number
• VARCHAR(n), or CHARACTER VARYING(n), a string value with maximum fixed width Trailing spaces are removed when converting a value to one of these types.
• CHAR(n), or CHARACTER(n), a string value with a fixed width. Values are truncated if longer, or padded with spaces if shorter, to be brought to the specified size.
• VARCHAR, or STRING, or TEXT: a string of unlimited length. Trailing spaces are removed when converting a CHAR(n) value to this type.
• BINARY(n), a byte string with a fixed width
• VARBINARY, a byte string with an unlimited width. BYTEA is an alias.
• NULL, a type comprising only the NULL value
• INTERVAL, a SQL interval. Two types of intervals are supported: long intervals (comprising years and months), and short intervals, comprising days, hours, minutes, seconds.
• TIME, time of the day.
• TIMESTAMP, a SQL timestamp without a timezone. A timestamp represents a value containing a date and a time.
• DATE, a SQL date without a timezone. A date represents a value containing a date (year, month, day).
• GEOMETRY: geographic data type (only rudimentary support at this point)
• ARRAY: used as a suffix for another type, as in INT ARRAY. An array with element of the specified type.

A suffix of NULL or NOT NULL can be appended to a type name to indicate the nullability. A type with no suffix is not nullable by default.

A type is nullable if it can represent the NULL value. For input tables the nullability of a column is declared explicitly. For intermediate results and output views the compiler infers the nullability of each column using type inference rules.

Most SQL operations are defined for nullable types. Our compiler follows the SQL standard in this respect. Most operations (e.g., +), when applied a NULL operand will produce a NULL value.

type:
      typeName
      [ collectionsTypeName ]*

typeName:
      sqlTypeName
  |   compoundIdentifier

sqlTypeName:
      char [ precision ] [ charSet ]
  |   varchar [ precision ] [ charSet ]
  |   DATE
  |   time
  |   timestamp
  |   GEOMETRY
  |   decimal [ precision [, scale] ]
  |   BOOLEAN
  |   integer
  |   BINARY [ precision ]
  |   varbinary [ precision ]
  |   TINYINT
  |   SMALLINT
  |   BIGINT
  |   REAL
  |   double
  |   FLOAT

collectionsTypeName:
      ARRAY

char:
      CHARACTER | CHAR

varchar:
      char VARYING | VARCHAR

decimal:
      DECIMAL | DEC | NUMERIC | NUMBER

integer:
      INTEGER | INT

varbinary:
      BINARY VARYING | VARBINARY

double:
      DOUBLE [ PRECISION ]

time:
      TIME [ precision ] [ timeZone ]

timestamp:
      TIMESTAMP [ precision ] [ timeZone ]

charSet:
      CHARACTER SET charSetName

timeZone:
      WITHOUT TIME ZONE

A compoundIdentifier is a sequence of identifiers separated by dots.