| org.apache.derby.iapi.store.access.DynamicCompiledOpenConglomInfo
All known Subclasses: org.apache.derby.impl.store.access.conglomerate.OpenConglomerateScratchSpace,
| DynamicCompiledOpenConglomInfo | | public interface DynamicCompiledOpenConglomInfo (Code) | | Information that can be "compiled" and reused per transaction per
open operation. This information is read only by the caller and
written by user. Likely information kept in this object is a set of
scratch buffers which will be used by openScan() and thus must not be
shared across multiple threads/openScan()'s/openConglomerate()'s. The
goal is to optimize repeated operations like btree inserts, by allowing a
set of scratch buffers to be reused across a repeated execution of a statement
like an insert/delete/update.
This information is obtained from the getDynamicCompiledConglomInfo(conglomid)
method call. It can then be used in openConglomerate() and openScan() calls
for increased performance. The information is only valid until the next
ddl operation is performed on the conglomerate. It is up to the caller to
provide an invalidation methodology.
The dynamic info is a set of variables to be used in a given ScanController
or ConglomerateController. It can only be used in one controller at a time.
It is up to the caller to insure the correct thread access to this info. The
type of info in this is a scratch template for btree traversal, other scratch
variables for qualifier evaluation, ...
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