ALLBASE/SQL Reference Manual (36216-90216)
328 Chapter10
SQL Statements A - D
CREATE DBEFILE
rounded based on the
DBEFileIncrSize
provided. If you
omit the MAXPAGES clause, the value defaults to the
ALLBASE/SQL DBEFile maximum size.
TYPE = specifies the setting of the DBEFile's TYPE attribute. The
following are valid settings:
TABLE Only data pages (table, HASH, or LONG) can be stored in
the DBEFile.
INDEX Only index pages can be stored in the DBEFile.
MIXED A mixture of data and index pages can be stored in the
DBEFile.
Description
• You use this statement to create all DBEFiles except DBEFile0, which is created when
a START DBE NEW statement is processed.
• The CREATE DBEFILE statement formats the DBEFile.The name and characteristics of
the DBEFile are stored in the system catalog.
• The DBEFile created is owned by hpdb and has the following permissions:
-rw-----
• To use a DBEFile for storing a table, LONG data, and/or an index, you add it to a
DBEFileSet with the ADD DBEFILE statement, then reference the name of the
DBEFileSet in the CREATE TABLE statement. You may add a DBEFile to the SYSTEM
DBEFileSet.
• To delete the row describing a DBEFile from SYSTEM.DBEFile, use the DROP
DBEFILE statement.
• INCREMENT and MAXPAGES are optional clauses. If they are omitted, no DBEFile
expansion takes place.
• It is highly recommended that you provide the
DBEFileMaxSize
along with the
DBEFileIncrSize
. Not specifying the
DBEFileMaxSize
causes it to be set to the
system maximum. This results in a high value for the ratio for this file. The
DBEFileMaxSize
is stored internally as an integer multiple of the
DBEFileIncrSize
;
if the
DBEFileMaxSize
is not a multiple of
DBEFileIncrSize
, rounding can occur.
Refer to the description of
DBEFileMaxSize
in the previous section for information on
the rounding process.
• The
DBEFileMaxSize
, after rounding, should be equal to or greater than the
DBEFileSize
. It should not exceed the maximum DBEFile size of 524,287 pages.
• The optimal
DBEFileIncrSize
depends on the expected rate of expansion for the file.
Refer to the section "Calculating Storage for Database Objects" in the ALLBASE/SQL
Database Administration Guide for information about estimating size requirements for
tables and indexes.
• Expandable DBEFiles do not expand dynamically during the creation of hash tables.