Type Members

1.  class KernelDeltaLogDelegator extends DeltaLogImpl

   We want to be able to construct an OptimisticTransactionImpl that uses a delta log and a snapshot provided by the Delta Kernel.

   We want to be able to construct an OptimisticTransactionImpl that uses a delta log and a snapshot provided by the Delta Kernel. OptimisticTransactionImpl takes a DeltaLogImpl and SnapshotImpl internally, so we need classes that extend those, and this is the one for DeltaLogImpl. It provides features used by flink+startTransaction.

2.  class KernelOptTxn extends OptimisticTransactionImpl
3.  class KernelSnapshotDelegator extends SnapshotImpl

   This class is designed to be passed to OptimisticTransactionImpl, and provide exactly what that needs to operate, but on a Kernel Snapshot rather than a standalone Snapshot.

   This class is designed to be passed to OptimisticTransactionImpl, and provide exactly what that needs to operate, but on a Kernel Snapshot rather than a standalone Snapshot.

   The methods/variables used by OptimisticTransactionImpl that we implement are:

   • protocolScala
   • metadataScala
   • version
   • getMetadata

   Other functions that are used, we do not implement, but fall back to standalone. These functions are only called in "exceptional" cases, so should not overly impact performance. They include:

   • scanScala (only called in markFilesAsRead, not used by flink)
   • transactions (only used in txnVersion, which is used only on first commit for a flink app)
     • This is a val, but it calls setTransactionsScala, so we log for that
   • numOfFiles (only used in verifySchemaCompatibility, which happens only when a metadata update occures)
   • allFilesScala (only used in verifySchemaCompatibility)
4.  class KernelSnapshotWrapper extends Snapshot

   Wrap a io.delta.kernel.Snapshot such that it conforms to the the io.delta.standalone.Snapshot interface.

   Wrap a io.delta.kernel.Snapshot such that it conforms to the the io.delta.standalone.Snapshot interface.

   NB: Currently only supports the getMetadata and getVersion methods. All others throw exceptions.