Github user ajantha-bhat commented on a diff in the pull request:
https://github.com/apache/carbondata/pull/2936#discussion_r235842114
--- Diff:
core/src/main/java/org/apache/carbondata/core/datamap/TableDataMap.java ---
@@ -120,37 +132,166 @@ public BlockletDetailsFetcher
getBlockletDetailsFetcher() {
* @param filterExp
* @return
*/
- public List<ExtendedBlocklet> prune(List<Segment> segments,
FilterResolverIntf filterExp,
- List<PartitionSpec> partitions) throws IOException {
- List<ExtendedBlocklet> blocklets = new ArrayList<>();
- SegmentProperties segmentProperties;
- Map<Segment, List<DataMap>> dataMaps =
dataMapFactory.getDataMaps(segments);
+ public List<ExtendedBlocklet> prune(List<Segment> segments, final
FilterResolverIntf filterExp,
+ final List<PartitionSpec> partitions) throws IOException {
+ final List<ExtendedBlocklet> blocklets = new ArrayList<>();
+ final Map<Segment, List<DataMap>> dataMaps =
dataMapFactory.getDataMaps(segments);
+ // for non-filter queries
+ if (filterExp == null) {
+ // if filter is not passed, then return all the blocklets.
+ return pruneWithoutFilter(segments, partitions, blocklets);
+ }
+ // for filter queries
+ int totalFiles = 0;
+ boolean isBlockDataMapType = true;
+ for (Segment segment : segments) {
+ for (DataMap dataMap : dataMaps.get(segment)) {
+ if (!(dataMap instanceof BlockDataMap)) {
+ isBlockDataMapType = false;
+ break;
+ }
+ totalFiles += ((BlockDataMap) dataMap).getTotalBlocks();
+ }
+ if (!isBlockDataMapType) {
+ // totalFiles fill be 0 for non-BlockDataMap Type. ex: lucene,
bloom datamap. use old flow.
+ break;
+ }
+ }
+ int numOfThreadsForPruning = getNumOfThreadsForPruning();
+ int filesPerEachThread = totalFiles / numOfThreadsForPruning;
+ if (numOfThreadsForPruning == 1 || filesPerEachThread == 1
+ || segments.size() < numOfThreadsForPruning || totalFiles
+ <
CarbonCommonConstants.CARBON_DRIVER_PRUNING_MULTI_THREAD_ENABLE_FILES_COUNT) {
+ // use multi-thread, only if the files are more than 0.1 million.
+ // As 0.1 million files block pruning can take only 1 second.
+ // Doing multi-thread for smaller values is not recommended as
+ // driver should have minimum threads opened to support multiple
concurrent queries.
+ return pruneWithFilter(segments, filterExp, partitions, blocklets,
dataMaps);
+ }
+ // handle by multi-thread
+ return pruneWithFilterMultiThread(segments, filterExp, partitions,
blocklets, dataMaps,
+ totalFiles);
+ }
+
+ private List<ExtendedBlocklet> pruneWithoutFilter(List<Segment> segments,
+ List<PartitionSpec> partitions, List<ExtendedBlocklet> blocklets)
throws IOException {
+ for (Segment segment : segments) {
+ List<Blocklet> allBlocklets =
blockletDetailsFetcher.getAllBlocklets(segment, partitions);
+ blocklets.addAll(
+
addSegmentId(blockletDetailsFetcher.getExtendedBlocklets(allBlocklets, segment),
+ segment.toString()));
+ }
+ return blocklets;
+ }
+
+ private List<ExtendedBlocklet> pruneWithFilter(List<Segment> segments,
+ FilterResolverIntf filterExp, List<PartitionSpec> partitions,
+ List<ExtendedBlocklet> blocklets, Map<Segment, List<DataMap>>
dataMaps) throws IOException {
for (Segment segment : segments) {
List<Blocklet> pruneBlocklets = new ArrayList<>();
- // if filter is not passed then return all the blocklets
- if (filterExp == null) {
- pruneBlocklets = blockletDetailsFetcher.getAllBlocklets(segment,
partitions);
- } else {
- segmentProperties =
segmentPropertiesFetcher.getSegmentProperties(segment);
- for (DataMap dataMap : dataMaps.get(segment)) {
- pruneBlocklets.addAll(dataMap.prune(filterExp,
segmentProperties, partitions));
+ SegmentProperties segmentProperties =
segmentPropertiesFetcher.getSegmentProperties(segment);
+ for (DataMap dataMap : dataMaps.get(segment)) {
+ pruneBlocklets.addAll(dataMap.prune(filterExp, segmentProperties,
partitions));
+ }
+ blocklets.addAll(
+
addSegmentId(blockletDetailsFetcher.getExtendedBlocklets(pruneBlocklets,
segment),
+ segment.toString()));
+ }
+ return blocklets;
+ }
+
+ private List<ExtendedBlocklet> pruneWithFilterMultiThread(List<Segment>
segments,
+ final FilterResolverIntf filterExp, final List<PartitionSpec>
partitions,
+ List<ExtendedBlocklet> blocklets, final Map<Segment, List<DataMap>>
dataMaps,
+ int totalFiles) {
+ int numOfThreadsForPruning = getNumOfThreadsForPruning();
+ int filesPerEachThread = (int) Math.ceil((double)totalFiles /
numOfThreadsForPruning);
+ int prev = 0;
+ int filesCount = 0;
+ int processedFileCount = 0;
+ List<List<Segment>> segmentList = new ArrayList<>();
--- End diff --
done
---
