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https://issues.apache.org/jira/browse/PARQUET-2226?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17677004#comment-17677004
]
ASF GitHub Bot commented on PARQUET-2226:
-----------------------------------------
wgtmac commented on code in PR #1020:
URL: https://github.com/apache/parquet-mr/pull/1020#discussion_r1070546933
##########
parquet-column/src/test/java/org/apache/parquet/column/values/bloomfilter/TestBlockSplitBloomFilter.java:
##########
@@ -181,6 +182,60 @@ public void testBloomFilterNDVs(){
assertTrue(bytes < 5 * 1024 * 1024);
}
+ @Test
+ public void testMergeBloomFilter() throws IOException {
+ Random random = new Random();
+ int numBytes = BlockSplitBloomFilter.optimalNumOfBits(1024 * 1024, 0.01) /
8;
+ BloomFilter otherBloomFilter = new BlockSplitBloomFilter(numBytes);
+ BloomFilter mergedBloomFilter = new BlockSplitBloomFilter(numBytes);
+
+ Set<String> originStrings = new HashSet<>();
+ Set<String> testStrings = new HashSet<>();
+ Set<Integer> testInts = new HashSet<>();
+ Set<Double> testDoubles = new HashSet<>();
+ Set<Float> testFloats = new HashSet<>();
+ for (int i = 0; i < 1024; i++) {
+
+ String originStrValue = RandomStringUtils.randomAlphabetic(1, 64);
+ originStrings.add(originStrValue);
+
mergedBloomFilter.insertHash(otherBloomFilter.hash(Binary.fromString(originStrValue)));
+
+ String testString = RandomStringUtils.randomAlphabetic(1, 64);
+ testStrings.add(testString);
+
otherBloomFilter.insertHash(otherBloomFilter.hash(Binary.fromString(testString)));
+
+ int testInt = random.nextInt();
+ testInts.add(testInt);
+ otherBloomFilter.insertHash(otherBloomFilter.hash(testInt));
+
+ double testDouble = random.nextDouble();
+ testDoubles.add(testDouble);
+ otherBloomFilter.insertHash(otherBloomFilter.hash(testDouble));
+
+ float testFloat = random.nextFloat();
+ testFloats.add(testFloat);
+ otherBloomFilter.insertHash(otherBloomFilter.hash(testFloat));
+ }
+ mergedBloomFilter.merge(otherBloomFilter);
+ for (String testString : originStrings) {
+
assertTrue(mergedBloomFilter.findHash(mergedBloomFilter.hash(Binary.fromString(testString))));
Review Comment:
Can you add some cases like below to have more coverage:
- value that is tested false on the original BF but true on the other side,
and vice versa?
- value that is tested false on both sides.
- value that is tested true on both sides.
##########
parquet-column/src/main/java/org/apache/parquet/column/values/bloomfilter/BlockSplitBloomFilter.java:
##########
@@ -394,4 +395,21 @@ public long hash(float value) {
public long hash(Binary value) {
return hashFunction.hashBytes(value.getBytes());
}
+
+ @Override
+ public void merge(BloomFilter otherBloomFilter) throws IOException {
+ Preconditions.checkArgument((otherBloomFilter.getAlgorithm() ==
getAlgorithm()),
Review Comment:
It would be more user-friendly to print the mismatched values on both sides.
##########
parquet-column/src/main/java/org/apache/parquet/column/values/bloomfilter/BloomFilter.java:
##########
@@ -176,4 +176,13 @@ public String toString() {
* @return compress algorithm that the bloom filter apply
*/
Compression getCompression();
+
+ /**
+ * Combines this Bloom filter with another Bloom filter by performing a
bitwise OR of the underlying bits
+ *
+ * @param otherBloomFilter The Bloom filter to combine this Bloom filter
with.
+ */
+ default void merge(BloomFilter otherBloomFilter) throws IOException {
+ throw new UnsupportedOperationException("Not supported merge operation.");
Review Comment:
```suggestion
throw new UnsupportedOperationException("Merge is not implemented.");
```
##########
parquet-column/src/test/java/org/apache/parquet/column/values/bloomfilter/TestBlockSplitBloomFilter.java:
##########
@@ -181,6 +182,60 @@ public void testBloomFilterNDVs(){
assertTrue(bytes < 5 * 1024 * 1024);
}
+ @Test
+ public void testMergeBloomFilter() throws IOException {
+ Random random = new Random();
+ int numBytes = BlockSplitBloomFilter.optimalNumOfBits(1024 * 1024, 0.01) /
8;
+ BloomFilter otherBloomFilter = new BlockSplitBloomFilter(numBytes);
+ BloomFilter mergedBloomFilter = new BlockSplitBloomFilter(numBytes);
+
+ Set<String> originStrings = new HashSet<>();
Review Comment:
Better to split different types into separate test cases.
> Support merge Bloom Filter
> --------------------------
>
> Key: PARQUET-2226
> URL: https://issues.apache.org/jira/browse/PARQUET-2226
> Project: Parquet
> Issue Type: Improvement
> Reporter: Mars
> Priority: Major
>
> We need to collect Parquet's bloom filter of multiple files, and then
> synthesize a more comprehensive bloom filter for common use.
> Guava supports similar api operations
> https://guava.dev/releases/31.0.1-jre/api/docs/src-html/com/google/common/hash/BloomFilter.html#line.252
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