/**
* Method to fetch table data
*
* @param table table name
* @param database database
* @return list of columns in comma seperated way
* @throws Exception if any error occurs
*/
private List<String> getTableData(String table, String database) throws Exception {
HiveConf conf = new HiveConf();
conf.addResource("hive-site.xml");
ArrayList<String> results = new ArrayList<String>();
ArrayList<String> temp = new ArrayList<String>();
Hive hive = Hive.get(conf);
org.apache.hadoop.hive.ql.metadata.Table tbl = hive.getTable(database, table);
FetchWork work;
if (!tbl.getPartCols().isEmpty()) {
List<Partition> partitions = hive.getPartitions(tbl);
List<PartitionDesc> partDesc = new ArrayList<PartitionDesc>();
List<String> partLocs = new ArrayList<String>();
for (Partition part : partitions) {
partLocs.add(part.getLocation());
partDesc.add(Utilities.getPartitionDesc(part));
}
work = new FetchWork(partLocs, partDesc, Utilities.getTableDesc(tbl));
work.setLimit(100);
} else {
work = new FetchWork(tbl.getDataLocation().toString(), Utilities.getTableDesc(tbl));
}
FetchTask task = new FetchTask();
task.setWork(work);
task.initialize(conf, null, null);
task.fetch(temp);
for (String str : temp) {
results.add(str.replace("\t", ","));
}
return results;
}
/**
* set the current task in the mapredWork.
*
* @param alias_id current alias
* @param topOp the top operator of the stack
* @param plan current plan
* @param local whether you need to add to map-reduce or local work
* @param opProcCtx processing context
* @param pList pruned partition list. If it is null it will be computed on-the-fly.
*/
public static void setTaskPlan(
String alias_id,
Operator<? extends Serializable> topOp,
MapredWork plan,
boolean local,
GenMRProcContext opProcCtx,
PrunedPartitionList pList)
throws SemanticException {
ParseContext parseCtx = opProcCtx.getParseCtx();
Set<ReadEntity> inputs = opProcCtx.getInputs();
ArrayList<Path> partDir = new ArrayList<Path>();
ArrayList<PartitionDesc> partDesc = new ArrayList<PartitionDesc>();
Path tblDir = null;
TableDesc tblDesc = null;
PrunedPartitionList partsList = pList;
if (partsList == null) {
try {
partsList = parseCtx.getOpToPartList().get((TableScanOperator) topOp);
if (partsList == null) {
partsList =
PartitionPruner.prune(
parseCtx.getTopToTable().get(topOp),
parseCtx.getOpToPartPruner().get(topOp),
opProcCtx.getConf(),
alias_id,
parseCtx.getPrunedPartitions());
parseCtx.getOpToPartList().put((TableScanOperator) topOp, partsList);
}
} catch (SemanticException e) {
throw e;
} catch (HiveException e) {
LOG.error(org.apache.hadoop.util.StringUtils.stringifyException(e));
throw new SemanticException(e.getMessage(), e);
}
}
// Generate the map work for this alias_id
Set<Partition> parts = null;
// pass both confirmed and unknown partitions through the map-reduce
// framework
parts = partsList.getConfirmedPartns();
parts.addAll(partsList.getUnknownPartns());
PartitionDesc aliasPartnDesc = null;
try {
if (!parts.isEmpty()) {
aliasPartnDesc = Utilities.getPartitionDesc(parts.iterator().next());
}
} catch (HiveException e) {
LOG.error(org.apache.hadoop.util.StringUtils.stringifyException(e));
throw new SemanticException(e.getMessage(), e);
}
// The table does not have any partitions
if (aliasPartnDesc == null) {
aliasPartnDesc =
new PartitionDesc(Utilities.getTableDesc(parseCtx.getTopToTable().get(topOp)), null);
}
plan.getAliasToPartnInfo().put(alias_id, aliasPartnDesc);
for (Partition part : parts) {
if (part.getTable().isPartitioned()) {
inputs.add(new ReadEntity(part));
} else {
inputs.add(new ReadEntity(part.getTable()));
}
// Later the properties have to come from the partition as opposed
// to from the table in order to support versioning.
Path[] paths;
sampleDesc sampleDescr = parseCtx.getOpToSamplePruner().get(topOp);
if (sampleDescr != null) {
paths = SamplePruner.prune(part, sampleDescr);
} else {
paths = part.getPath();
}
// is it a partitioned table ?
if (!part.getTable().isPartitioned()) {
assert ((tblDir == null) && (tblDesc == null));
tblDir = paths[0];
tblDesc = Utilities.getTableDesc(part.getTable());
}
for (Path p : paths) {
if (p == null) {
continue;
}
String path = p.toString();
if (LOG.isDebugEnabled()) {
LOG.debug("Adding " + path + " of table" + alias_id);
}
partDir.add(p);
try {
partDesc.add(Utilities.getPartitionDesc(part));
} catch (HiveException e) {
LOG.error(org.apache.hadoop.util.StringUtils.stringifyException(e));
throw new SemanticException(e.getMessage(), e);
}
}
}
Iterator<Path> iterPath = partDir.iterator();
Iterator<PartitionDesc> iterPartnDesc = partDesc.iterator();
if (!local) {
while (iterPath.hasNext()) {
assert iterPartnDesc.hasNext();
String path = iterPath.next().toString();
PartitionDesc prtDesc = iterPartnDesc.next();
// Add the path to alias mapping
if (plan.getPathToAliases().get(path) == null) {
plan.getPathToAliases().put(path, new ArrayList<String>());
}
plan.getPathToAliases().get(path).add(alias_id);
plan.getPathToPartitionInfo().put(path, prtDesc);
if (LOG.isDebugEnabled()) {
LOG.debug("Information added for path " + path);
}
}
assert plan.getAliasToWork().get(alias_id) == null;
plan.getAliasToWork().put(alias_id, topOp);
} else {
// populate local work if needed
MapredLocalWork localPlan = plan.getMapLocalWork();
if (localPlan == null) {
localPlan =
new MapredLocalWork(
new LinkedHashMap<String, Operator<? extends Serializable>>(),
new LinkedHashMap<String, FetchWork>());
}
assert localPlan.getAliasToWork().get(alias_id) == null;
assert localPlan.getAliasToFetchWork().get(alias_id) == null;
localPlan.getAliasToWork().put(alias_id, topOp);
if (tblDir == null) {
localPlan
.getAliasToFetchWork()
.put(alias_id, new FetchWork(FetchWork.convertPathToStringArray(partDir), partDesc));
} else {
localPlan.getAliasToFetchWork().put(alias_id, new FetchWork(tblDir.toString(), tblDesc));
}
plan.setMapLocalWork(localPlan);
}
}
