Maximum Settings Constants

Windows

Last modified: January 09, 2012

Applies to: Windows | Windows Server

These constants provide the maximum settings that are allowed on items in an ESE database.

Constant/value

Description

JET_BASE_NAME_LENGTH
3

Sets the length for the prefix used to name files that are used by the database engine. This length is applicable to the name set for the JET_paramBaseName system parameter.

JET_MAX_COMPUTERNAME_LENGTH
15

Sets the maximum length for JET_SIGNATURE.

JET_cbBookmarkMost
256

The default maximum size of a bookmark. This is valid when the key size is left at its default value.

JET_cbBookmarkMostMost
2000

The maximum size of a bookmark when esent is configured to have the largest keys possible.

Windows 7: JET_cbBookmarkMostMost is introduced in Windows 7.

JET_cbNameMost
64

The maximum length of a object, column, index, or property name.

Note  If Unicode, the value is 128.

JET_cbFullNameMost
255

The maximum length of a "name.name.name..." construct.

Note  If Unicode, the value is 510.

JET_cbColumnLVPageOverhead
82

This number can be used to compute the maximum amount of a BLOB that can be stored by the database engine on a single database page. The formula is max size = JET_paramDatabasePageSize–JET_cbColumnLVPageOverhead.

This value is now obsolete. The long-value chunk size should be retrieved with the JET_paramLVChunkSizeMost parameter.

JET_cbColumnMost
255

The maximum size of non-long-value column data.

JET_cbLVDefaultValueMost
255

The maximum size of a long-value (LongBinary or LongText) column default value.

JET_cbKeyMost
255

The default maximum size of a sort or index key.

JET_cbKeyMostMost
2000

The maximum configurable size of a sort or index key for any page size. (See JET_INDEXCREATE2.cbKeyMost)

Windows 7: JET_cbKeyMostMost is introduced in the Windows 7 operating system.

JET_cbKeyMost2KBytePage
500

The maximum allowable maximum configurable size for an index key in a database using 2048 byte pages. See JET_INDEXCREATE for more information.

Windows Vista: JET_cbKeyMost2KBytePage is introduced in the Windows Vista operating system.

JET_cbKeyMost4KBytePage
1000

The maximum allowable maximum configurable size for an index key in a database using 4096 byte pages. See JET_INDEXCREATE for more information.

Windows Vista: JET_cbKeyMost4KBytePage is introduced in Windows Vista.

JET_cbKeyMost8KBytePage
2000

The maximum allowable maximum configurable size for an index key in a database using 8192 byte pages. See JET_INDEXCREATE for more information.

Windows Vista:  JET_cbKeyMost8KBytePage is introduced in Windows Vista

JET_cbKeyMostMin
255

The minimum allowable maximum size for an index key. See JET_INDEXCREATE for more information.

Windows Vista:  JET_cbKeyMostMin is introduced in Windows Vista.

JET_cbLimitKeyMost
256

The maximum key size when the key is formed by using a limit grbit, such as JET_bitStrLimit, which is used in the JetMakeKey function.

JET_cbPrimaryKeyMost
255

The maximum size of the primary index. This is now obsolete.

JET_cbSecondaryKeyMost
255

The maximum size of the secondary index. This is now obsolete.

JET_ccolKeyMost
12

The maximum number of components in a sort or index key.

Windows Vista:  In Windows Vista and later versions of Windows the value is 16.

JET_ccolMost
0x0000fee0

The maximum number of columns allowed in a table.

Windows XP:  The value 0x0000fee0 is used in Windows XP and later and later versions of Windows

Windows 2000:  The value 0x00007ffe is used in Windows 2000.

JET_ccolFixedMost
0x0000007f

The maximum number of fixed columns allowed in a table, currently 127.

JET_ccolVarMost
0x00000080

The maximum number of variable-length columns that can be contained in a table, currently 128.

JET_ccolTaggedMost
( JET_ccolMost - 0x000000ff )

The maximum number of tagged columns that can be contained in a table, currently 64993.

Requirements

Client

Requires Windows Vista, Windows XP, or Windows 2000 Professional.

Server

Requires Windows Server 2008, Windows Server 2003, or Windows 2000 Server.

Header

Declared in Esent.h.

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