Vertica Analytics Platform Version 9.2.x Documentation

Identifiers

Identifiers (names) of objects such as schema, table, projection, column names, and so on, can be up to 128 bytes in length.

Unquoted Identifiers

Unquoted SQL identifiers must begin with one of the following:

  • Non-Unicode letters: A–Z or a-z
  • Underscore (_)

Subsequent characters in an identifier can be any combination of the following:

  • Non-Unicode letters: A–Z or a-z
  • Underscore (_)
  • Digits(0–9)
  • Unicode letters (letters with diacriticals or not in the Latin alphabet), unsupported for model names
  • Dollar sign ($), unsupported for model names

    The SQL standard does not support dollar sign in identifiers, so usage can cause application portability problems.

Quoted Identifiers

Quoted identifiers are not supported for model names

Identifiers enclosed in double quote (") characters can contain any character. If you want to include a double quote, you need a pair of them; for example """". You can use names that would otherwise be invalid—for example, names that include only numeric characters ("123") or contain space characters, punctuation marks, and SQL or Vertica‑reserved keywords. For example:

CREATE SEQUENCE "my sequence!";

Double quotes are required for non-alphanumerics and SQL keywords such as "1time", "Next week" and "Select".

Case Sensitivity

Identifiers are not case-sensitive. Thus, identifiers "ABC", "ABc", and "aBc" are synonymous, as are ABC, ABc, and aBc.

Non-ASCII Characters

Vertica accepts non-ASCII UTF-8 Unicode characters for table names, column names, and other identifiers, extending the cases where upper/lower case distinctions are ignored (case-folded) to all alphabets, including Latin, Cyrillic, and Greek.

For example, the following CREATE TABLE statement uses the ß (German eszett) in the table name:

=> CREATE TABLE straße(x int, y int);
   CREATE TABLE

Identifiers Are Stored As Created

SQL identifiers, such as table and column names, are not converted to lowercase. They are stored as created, and references to them are resolved using case-insensitive compares. For example, the following statement creates table ALLCAPS.

=> CREATE TABLE ALLCAPS(c1 varchar(30));
=> INSERT INTO ALLCAPS values('upper case');

The following statements are variations of the same query:

=> SELECT * FROM ALLCAPS;
=> SELECT * FROM allcaps;
=> SELECT * FROM "allcaps";

The three queries all return the same result:

     c1
------------
 upper case
(1 row)

Note that Vertica returns an error if you try to create table AllCaps:

=> CREATE TABLE AllCaps(c1 varchar(30));
   ROLLBACK:  table "AllCaps" already exists

See QUOTE_IDENT for additional information.