Informational Parameters
Applies to: Windows | Windows Server
Informational Parameters
This topic contains parameters that are used to expose information about the database engine.
JET_paramKeyMost
134
This read-only parameter indicates the maximum allowable index key length that can be selected for the current database page size (as configured by JET_paramDatabasePageSize).
| Label | Value |
|---|---|
Default Value: |
JET_cbKeyMost4KBytePage |
Type: |
Integer |
Valid Range: |
255 – 65535 |
Scope: |
Global |
Set After JetCreateInstance: |
N/A |
Set after JetInit: |
N/A |
Affects Physical Layout: |
No |
Affects Reliability: |
No |
Affects Performance: |
No |
Affects Resources: |
No |
Availability: |
Starting with Windows Server 2008 and Windows Vista |
JET_paramMaxColtyp
131
This read only parameter returns the maximum JET_COLTYP (JET_coltypMax) for that version of the database engine. This value can be used to test for support of a specific JET_COLTYP. If a given JET_COLTYP is less than the value of this parameter then it is supported by the database engine.
| Label | Value |
|---|---|
Default Value: |
JET_coltypUnsignedShort + 1 |
Type: |
Integer |
Valid Range: |
0 – 255 |
Scope: |
Global |
Set After JetCreateInstance: |
N/A |
Set after JetInit: |
N/A |
Affects Physical Layout: |
No |
Affects Reliability: |
No |
Affects Performance: |
No |
Affects Resources: |
No |
Availability: |
Starting with Windows Server 2008 and Windows Vista |
JET_paramLVChunkSizeMost
163
Read only parameter that returns the long-value chunk size based on configured page size. If a long-value is to be read or written with multiple Jet{Set,Retrieve}Column calls then using a buffer whose size is a multiple of the chunk size is more efficient.
| Label | Value |
|---|---|
Default Value: |
2kb page = 1966 bytes |
Type: |
Integer |
Valid Range: |
0-10000 |
Scope: |
|
Set After JetCreateInstance: |
|
Set after JetInit: |
|
Affects Physical Layout: |
|
Affects Reliability: |
|
Affects Performance: |
|
Affects Resources: |
|
Availability: |
Requirements
| Requirement | Value |
|---|---|
Client |
Requires Windows Vista. |
Server |
Requires Windows Server 2008. |
Header |
Declared in Esent.h. |