/**
* Returns the first location (HDFS path) that Impala does not have WRITE access to, or an null if
* none is found. For an unpartitioned table, this just checks the hdfsBaseDir. For a partitioned
* table it checks all partition directories.
*/
public String getFirstLocationWithoutWriteAccess() {
if (getMetaStoreTable() == null) return null;
if (getMetaStoreTable().getPartitionKeysSize() == 0) {
if (!TAccessLevelUtil.impliesWriteAccess(accessLevel_)) {
return hdfsBaseDir_;
}
} else {
for (HdfsPartition partition : partitions_) {
if (!TAccessLevelUtil.impliesWriteAccess(partition.getAccessLevel())) {
return partition.getLocation();
}
}
}
return null;
}
/**
* Create HdfsPartition objects corresponding to 'partitions'.
*
* <p>If there are no partitions in the Hive metadata, a single partition is added with no
* partition keys.
*
* <p>For files that have not been changed, reuses file descriptors from oldFileDescMap.
*/
private void loadPartitions(
List<org.apache.hadoop.hive.metastore.api.Partition> msPartitions,
org.apache.hadoop.hive.metastore.api.Table msTbl,
Map<String, FileDescriptor> oldFileDescMap)
throws IOException, CatalogException {
partitions_.clear();
hdfsBaseDir_ = msTbl.getSd().getLocation();
List<FileDescriptor> newFileDescs = Lists.newArrayList();
// INSERT statements need to refer to this if they try to write to new partitions
// Scans don't refer to this because by definition all partitions they refer to
// exist.
addDefaultPartition(msTbl.getSd());
if (msTbl.getPartitionKeysSize() == 0) {
Preconditions.checkArgument(msPartitions == null || msPartitions.isEmpty());
// This table has no partition key, which means it has no declared partitions.
// We model partitions slightly differently to Hive - every file must exist in a
// partition, so add a single partition with no keys which will get all the
// files in the table's root directory.
addPartition(msTbl.getSd(), null, new ArrayList<LiteralExpr>(), oldFileDescMap, newFileDescs);
Path location = new Path(hdfsBaseDir_);
if (DFS.exists(location)) {
accessLevel_ = getAvailableAccessLevel(location);
}
} else {
// keep track of distinct partition key values and how many nulls there are
Set<String>[] uniquePartitionKeys = new HashSet[numClusteringCols_];
long[] numNullKeys = new long[numClusteringCols_];
for (int i = 0; i < numClusteringCols_; ++i) {
uniquePartitionKeys[i] = new HashSet<String>();
numNullKeys[i] = 0;
}
for (org.apache.hadoop.hive.metastore.api.Partition msPartition : msPartitions) {
// load key values
List<LiteralExpr> keyValues = Lists.newArrayList();
int i = 0;
for (String partitionKey : msPartition.getValues()) {
uniquePartitionKeys[i].add(partitionKey);
// Deal with Hive's special NULL partition key.
if (partitionKey.equals(nullPartitionKeyValue_)) {
keyValues.add(new NullLiteral());
++numNullKeys[i];
} else {
ColumnType type = colsByPos_.get(keyValues.size()).getType();
try {
Expr expr = LiteralExpr.create(partitionKey, type);
// Force the literal to be of type declared in the metadata.
expr = expr.castTo(type);
keyValues.add((LiteralExpr) expr);
} catch (AnalysisException ex) {
LOG.warn("Failed to create literal expression of type: " + type, ex);
throw new InvalidStorageDescriptorException(ex);
}
}
++i;
}
HdfsPartition partition =
addPartition(msPartition.getSd(), msPartition, keyValues, oldFileDescMap, newFileDescs);
// If the partition is null, its HDFS path does not exist, and it was not added to
// this table's partition list. Skip the partition.
if (partition == null) continue;
if (msPartition.getParameters() != null) {
partition.setNumRows(getRowCount(msPartition.getParameters()));
}
if (!TAccessLevelUtil.impliesWriteAccess(partition.getAccessLevel())) {
// TODO: READ_ONLY isn't exactly correct because the it's possible the
// partition does not have READ permissions either. When we start checking
// whether we can READ from a table, this should be updated to set the
// table's access level to the "lowest" effective level across all
// partitions. That is, if one partition has READ_ONLY and another has
// WRITE_ONLY the table's access level should be NONE.
accessLevel_ = TAccessLevel.READ_ONLY;
}
}
// update col stats for partition key cols
for (int i = 0; i < numClusteringCols_; ++i) {
ColumnStats stats = colsByPos_.get(i).getStats();
stats.setNumNulls(numNullKeys[i]);
stats.setNumDistinctValues(uniquePartitionKeys[i].size());
LOG.debug("#col=" + Integer.toString(i) + " stats=" + stats.toString());
}
}
if (newFileDescs.size() > 0) {
loadBlockMd(newFileDescs);
}
uniqueHostPortsCount_ = countUniqueDataNetworkLocations(partitions_);
}
// True if Impala has HDFS write permissions on the hdfsBaseDir (for an unpartitioned
// table) or if Impala has write permissions on all partition directories (for
// a partitioned table).
public boolean hasWriteAccess() {
return TAccessLevelUtil.impliesWriteAccess(accessLevel_);
}