TableScanOperator tableScanOp,
ExprNodeGenericFuncDesc originalPredicate,
OpWalkerInfo owi,
HiveConf hiveConf) {
TableScanDesc tableScanDesc = tableScanOp.getConf();
Table tbl = owi.getParseContext().getTopToTable().get(tableScanOp);
if (HiveConf.getBoolVar(hiveConf, HiveConf.ConfVars.HIVEOPTINDEXFILTER)) {
// attach the original predicate to the table scan operator for index
// optimizations that require the pushed predicate before pcr & later
// optimizations are applied
tableScanDesc.setFilterExpr(originalPredicate);
}
if (!tbl.isNonNative()) {
return originalPredicate;
}
HiveStorageHandler storageHandler = tbl.getStorageHandler();
if (!(storageHandler instanceof HiveStoragePredicateHandler)) {
// The storage handler does not provide predicate decomposition
// support, so we'll implement the entire filter in Hive. However,
// we still provide the full predicate to the storage handler in
// case it wants to do any of its own prefiltering.
tableScanDesc.setFilterExpr(originalPredicate);
return originalPredicate;
}
HiveStoragePredicateHandler predicateHandler =
(HiveStoragePredicateHandler) storageHandler;
JobConf jobConf = new JobConf(owi.getParseContext().getConf());
Utilities.setColumnNameList(jobConf, tableScanOp);
Utilities.setColumnTypeList(jobConf, tableScanOp);
Utilities.copyTableJobPropertiesToConf(
Utilities.getTableDesc(tbl),
jobConf);
Deserializer deserializer = tbl.getDeserializer();
HiveStoragePredicateHandler.DecomposedPredicate decomposed =
predicateHandler.decomposePredicate(
jobConf,
deserializer,
originalPredicate);
if (decomposed == null) {
// not able to push anything down
if (LOG.isDebugEnabled()) {
LOG.debug("No pushdown possible for predicate: "
+ originalPredicate.getExprString());
}
return originalPredicate;
}
if (LOG.isDebugEnabled()) {
LOG.debug("Original predicate: "
+ originalPredicate.getExprString());
if (decomposed.pushedPredicate != null) {
LOG.debug(
"Pushed predicate: "
+ decomposed.pushedPredicate.getExprString());
}
if (decomposed.residualPredicate != null) {
LOG.debug(
"Residual predicate: "
+ decomposed.residualPredicate.getExprString());
}
}
tableScanDesc.setFilterExpr(decomposed.pushedPredicate);
return (ExprNodeGenericFuncDesc)decomposed.residualPredicate;
}