Firebird 2.1 Language Reference Update

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DDL statements -- the following queries will use ix_upname: select * from persons order by upper(name); select * from persons where upper(name) starting with 'VAN'; delete from persons where upper(name) = 'BROWN'; delete from persons where upper(name) = 'BROWN' and age > 65; create descending index ix_events_yt on MyEvents computed by (extract(year from StartDate) || Town); commit; -- the following query will use ix_events_yt: select * from MyEvents order by extract(year from StartDate) || Town desc; Maximum index key length increased Changed in: 2.0 Description: The maximum length of index keys, which used to be fixed at 252 bytes, is now equal to 1/4 of the page size, i.e. varying from 256 to 4096. The maximum indexable string length in bytes is 9 less than the key length. The table below shows the indexable string lengths in characters for the various page sizes and character sets. Table 5.2. Maximum indexable (VAR)CHAR length Page size Maximum indexable string length per charset type 1 byte/char 2 bytes/char 3 bytes/char 4 bytes/char 1024 247 123 82 61 2048 503 251 167 125 4096 1015 507 338 253 8192 2039 1019 679 509 16384 4087 2043 1362 1021 Maximum number of indices per table increased Changed in: 1.0.3, 1.5, 2.0 Description: The maximum number of 65 indices per table has been removed in Firebird 1.0.3, reintroduced at the higher level of 257 in Firebird 1.5, and removed once again in Firebird 2.0. Although there is no longer a “hard” ceiling, the number of indices creatable in practice is still limited by the database page size and the number of columns per index, as shown in the table below. 27
Table 5.3. Max. indices per table, Firebird 2.0 Page size DDL statements Number of indices depending on column count 1 col 2 cols 3 cols 1024 50 35 27 2048 101 72 56 4096 203 145 113 8192 408 291 227 16384 818 584 454 Please be aware that under normal circumstances, even 50 indices is way too many and will drastically reduce mutation speeds. The maximum was removed to accommodate data-warehousing applications and the like, which perform lots of bulk operations with the indices temporarily inactivated. For a full table also including Firebird versions 1.0–1.5, see the Notes at the end of the book. REVOKE ADMIN OPTION Available in: DSQL Added in: 2.0 Privileges: GRANT and REVOKE Description: Revokes a previously granted admin option (the right to pass on a granted role to others) from the grantee, without revoking the role itself. Multiple roles and/or multiple grantees can be handled in one statement. Syntax: Example: REVOKE ADMIN OPTION FOR FROM ::= role [, role ...] ::= [USER] [, [USER] ...] ::= username | PUBLIC revoke admin option for manager from john, paul, george, ringo If a user has received the admin option from several grantors, each of those grantors must revoke it or the user will still be able to grant the role(s) in question to others. 28
Page 1 and 2: Firebird 2.1 Language Reference Upd
Page 4 and 5: Table of Contents 1. Introduction .
Page 6 and 7: Firebird 2.1 Language Ref. Update F
Page 8 and 9: Firebird 2.1 Language Ref. Update A
Page 10 and 11: Firebird 2.1 Language Ref. Update s
Page 12 and 13: Chapter 1 Introduction Subject matt
Page 14 and 15: Chapter 2 Reserved words and keywor
Page 16 and 17: LOCK LOG LOG10 LPAD MATCHED MATCHIN
Page 18 and 19: Chapter 3 Available in: DSQL, PSQL
Page 20 and 21: Example: select name, age, case upp
Page 22 and 23: Data types and subtypes • Partial
Page 24 and 25: Added in: 1.0, 1.5, 1.5.1, 2.0, 2.1
Page 26 and 27: Chapter 5 DDL statements The statem
Page 28 and 29: With a special attribute (case-sens
Page 30 and 31: DIFFERENCE FILE parameter Added in:
Page 32 and 33: CREATE DOMAIN Available in: DSQL, E
Page 34 and 35: Example: DDL statements create exce
Page 36 and 37: Syntax: Example: ALTER EXTERNAL FUN
Page 40 and 41: DDL statements PROCEDURE A stored p
Page 42 and 43: DDL statements Description: Firebir
Page 44 and 45: DDL statements NOT NULL in variable
Page 46 and 47: CREATE GENERATOR Available in: DSQL
Page 48 and 49: Better alternative: DROP SEQUENCE D
Page 50 and 51: ) DDL statements lastname varchar(2
Page 52 and 53: USING INDEX subclause Available in:
Page 54 and 55: ALTER COLUMN: SET DEFAULT Available
Page 56 and 57: UNIQUE constraints now allow NULLs
Page 58 and 59: Example: DDL statements create trig
Page 60 and 61: Multi-action triggers Added in: 1.5
Page 62 and 63: NOT NULL in variable declarations C
Page 64 and 65: DDL statements Restriction on recre
Page 66 and 67: DDL statements got a chance to put
Page 68 and 69: ORDER BY Available in: DSQL, PSQL A
Page 70 and 71: DML statements ROWS can also be use
Page 72 and 73: DML statements COLLATE in variable
Page 74 and 75: The same call in ESQL (with obligat
Page 76 and 77: DML statements Description: A SELEC
Page 78 and 79: DML statements Aggregate functions
Page 80 and 81: Syntax: Example: Notes: ::= DML
Page 82 and 83: DML statements select d.dept_no, d.
Page 84 and 85: DML statements FIRST and SKIP are b
Page 86 and 87: DML statements select strlen(lastna
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DML statements Description: A natur
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DML statements • Only non-negativ
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Example: DML statements plan (MyTab
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UNIONs in subqueries Changed in: 2.
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Restrictions DML statements • The
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DML statements Description: Limits
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Chapter 7 Available in: DSQL Added
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Transaction control statements If t
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Transaction control statements •
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Chapter 8 PSQL statements PSQL - Pr
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PSQL statements • If sql_datatype
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Warning PSQL statements If you chan
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PSQL statements exception ex_bad_ty
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PSQL statements as declare variable
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Examples: PSQL statements thoroughl
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leave; end end c = 0; PSQL statemen
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Chapter 9 Available in: DSQL, PSQL
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Changed in: 2.0 Context variables D
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Context variables its execution was
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Context variables Description: OLD
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Chapter 10 Changed in: 2.0 Operator
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UNION as subselect Changed in: 2.0
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Chapter 11 Aggregate functions Aggr
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Chapter 12 Available in: DSQL, PSQL
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• If the argument is NULL, NULL i
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Result type: INTEGER or BIGINT Synt
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Result type: INTEGER Syntax: BIT_LE
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Internal functions This gives you c
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Available in: DSQL, PSQL Added in:
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Example: The equivalent CASE constr
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WEEK Bug alert Internal functions M
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Added in: 2.1 Internal functions De
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Internal functions • If x is nega
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Examples: Internal functions lpad (
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Internal functions This will return
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Internal functions overlay ('Goodby
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Internal functions Description: Cre
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Internal functions reverse ('Was it
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Added in: 2.1 Internal functions De
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Syntax: SINH (number) Important Int
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Notes: Internal functions • If th
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Description: Returns the arc cosine
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Declaration: External functions (UD
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Library: ib_udf Changed in: 1.0, 2.
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Better alternative: Internal functi
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External functions (UDFs) Descripti
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Syntax: cot (angle) Declaration: Ex
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Declaration: External functions (UD
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Library: ib_udf Added in: IB Change
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Changed in: 1.5, 1.5.2, 2.0 Better
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External functions (UDFs) DECLARE E
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See sright. Library: fbudf Added in
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Notes: External functions (UDFs) Fo
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Syntax: sign (number) Declaration:
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Library: fbudf Added in: 1.0 (Win),
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Notes: External functions (UDFs) th
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Better alternative: Internal functi
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Appendix A: Notes Character set NON
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Table A.1. How TPB settings affect
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Notes A note on CSTRING parameters
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Notes Maximum number of indices in
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Document History DDL statements ::
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Document History Internal functions
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Appendix C: License notice The cont
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Firebird 2.1 Language Reference Update

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