CacheSize (Property)

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Equivalence
Retrieving the records
Managing the CacheSize property
hQueryWithoutCorrection constant

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HFSQL properties

CacheSize (Property)

In french: TailleCache

Available only with these kinds of connection

The CacheSize property is used to:

Get the maximum number of records that can be stored in the cache of the Native MySQL Connector.
Change the maximum number of records that can be stored in the cache of the Native MySQL Connector. In this case, if the connection is currently opened, it will be closed and reopened with the new parameters during the first access to a file that uses this connection.

Remark: The connection can correspond to:

a connection described in the data model editor,
a connection described by HConnect, HDescribeConnection or HOpenConnection.
a connection described by a Connection variable.

Example

// Change the cache size of the Native MySQL Connector used by
// MyConnection
MyConnection.CacheSize = 450

Syntax

Getting the cache size for a connection Hide the details

<Cache size> = <Connection used>.CacheSize

<Cache size>: Integer

Cache size of the Native MySQL Connector.
If this parameter corresponds to:
-2: the cache size is the default size (100 for the Native MySQL Connector).
-1: the cache size is unlimited.
0: the cache stores no record. No record is retrieved.

<Connection used>: Character string or Connection variable

Name of the connection used. This name was defined:
in the data model editor,
by HDescribeConnection or HOpenConnection,
by the Connection type.

Defining the cache size for a connection Hide the details

<Connection used>.CacheSize = <Cache size>

<Connection used>: Character string or Connection variable

Name of the connection used. This name was defined:
in the data model editor,
by HDescribeConnection or HOpenConnection,
by the Connection type.

<Cache size>: Integer

New cache size of the Native MySQL Connector.
If this parameter corresponds to:
-2: the cache size will be the default size (100 for the Native MySQL Connector).
-1: the cache size will be unlimited.
0: the cache will store no record. No record will be retrieved.

Remarks

Equivalence

CtCacheSize is used to define the cache size for a MySQL connection. This property is kept for backward compatibility. It is recommended to use the CacheSize property.

Retrieving the records

The speed at which the entire set of records is retrieved is proportional to the cache size: the larger the cache size, the faster the records are retrieved.

However, the smaller the cache size, the faster the first record will be read.

Caution: The memory used by the cache is proportional to the cache size.

Managing the CacheSize property

The CacheSize property is supported only by the Native MySQL Connector.

Other Native Connectors do not support the CacheSize property. In this case, the use of this property will be ignored and no error will be generated.

hQueryWithoutCorrection constant

If the query is run while no check is performed on the SQL code (hQueryWithoutCorrection constant): the size is unlimited and cannot be changed with the CacheSize property.