yashmayya commented on code in PR #13835: URL: https://github.com/apache/pinot/pull/13835#discussion_r1720962052
########## pinot-segment-spi/src/main/java/org/apache/pinot/segment/spi/AggregationFunctionType.java: ########## @@ -344,6 +346,55 @@ public static AggregationFunctionType getAggregationFunctionType(String function } } + public static int compareFunctionParametersForStarTree(AggregationFunctionType functionType, + Map<String, Object> configuration1, Map<String, Object> configuration2) { + switch (functionType) { + case DISTINCTCOUNTHLL: + case DISTINCTCOUNTRAWHLL: { + // Compare the log2m value accounting for defaults + if ((MapUtils.isEmpty(configuration1) || !configuration1.containsKey(Constants.HLL_LOG2M_KEY)) + && (MapUtils.isEmpty(configuration2) || !configuration2.containsKey(Constants.HLL_LOG2M_KEY))) { + return 0; + } + if ((MapUtils.isEmpty(configuration1) || !configuration1.containsKey(Constants.HLL_LOG2M_KEY))) { + return Integer.compare(CommonConstants.Helix.DEFAULT_HYPERLOGLOG_LOG2M, Integer.parseInt(String.valueOf( + configuration2.get(Constants.HLL_LOG2M_KEY)))); + } + if ((MapUtils.isEmpty(configuration2)) || !configuration2.containsKey(Constants.HLL_LOG2M_KEY)) { + return Integer.compare(Integer.parseInt(String.valueOf(configuration1.get(Constants.HLL_LOG2M_KEY))), + CommonConstants.Helix.DEFAULT_HYPERLOGLOG_LOG2M); + } + return Integer.compare(Integer.parseInt(String.valueOf(configuration1.get(Constants.HLL_LOG2M_KEY))), + Integer.parseInt(String.valueOf(configuration2.get(Constants.HLL_LOG2M_KEY)))); + } + + case DISTINCTCOUNTHLLPLUS: + case DISTINCTCOUNTRAWHLLPLUS: { + // Only p value needs to be compared; HyperLogLogPlus with any sp value can be merged as long as p value is the + // same + if ((MapUtils.isEmpty(configuration1) || !configuration1.containsKey(Constants.HLLPLUS_ULL_P_KEY)) + && (MapUtils.isEmpty(configuration2) || !configuration2.containsKey(Constants.HLLPLUS_ULL_P_KEY))) { + return 0; + } + if ((MapUtils.isEmpty(configuration1) || !configuration1.containsKey(Constants.HLLPLUS_ULL_P_KEY))) { + return Integer.compare(CommonConstants.Helix.DEFAULT_HYPERLOGLOG_PLUS_P, + Integer.parseInt(String.valueOf(configuration2.get(Constants.HLLPLUS_ULL_P_KEY)))); + } + if ((MapUtils.isEmpty(configuration2) || !configuration2.containsKey(Constants.HLLPLUS_ULL_P_KEY))) { + return Integer.compare(Integer.parseInt(String.valueOf(configuration1.get(Constants.HLLPLUS_ULL_P_KEY))), + CommonConstants.Helix.DEFAULT_HYPERLOGLOG_PLUS_P); + } + return Integer.compare(Integer.parseInt(String.valueOf(configuration1.get(Constants.HLLPLUS_ULL_P_KEY))), + Integer.parseInt(String.valueOf(configuration2.get(Constants.HLLPLUS_ULL_P_KEY)))); + } + + // By default, assume that the rest of the aggregation functions do not have relevant configurations to be checked + // for a star-tree index + default: + return 0; Review Comment: While this is definitely true for some aggregation functions like `COUNT` / `MIN` / `MAX` / `SUM` / `AVG` / `MINMAXRANGE` / `DISTINCTCOUNTBITMAP` / `PERCENTILEEST`, it's a little more nuanced for certain other aggregation functions like `DISTINCTCOUNTULL` and `SUMPRECISION` when there is a mismatch in the query time aggregation parameter value (different `p` value for `DISTINCTCOUNTULL`, different precision value for `SUMPRECISION`) and the star-tree index aggregation parameter value. In these cases, there will never be a query error since intermediate results with any parameter value can be merged but the result could have lower / higher precision than desired by the user. On second thought, I'm wondering if it might just be better to do a stricter parameter match for these aggregation functions too. -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: commits-unsubscr...@pinot.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org --------------------------------------------------------------------- To unsubscribe, e-mail: commits-unsubscr...@pinot.apache.org For additional commands, e-mail: commits-h...@pinot.apache.org