Maximum Settings Constants

Applies to: Windows | Windows Server

Maximum Settings Constants

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

Requirement	Value
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.