Support order-by on BYTES column #5213
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In order to support order-by on BYTES column everywhere, inside the system we should always use ByteArray (comparable) to store the BYTES value. Currently BYTES value are stored as byte[], ByteArray or String in different places, which is very confusing and could cause casting errors. Changes: - For DisctinctCount, fix the casting issue when ordering on BYTES column - For selection order-by, order BYTES column using ByteArray instead of String for performance improvement - Inside Record, always store BYTES as ByteArray for clarity and also performance improvement (avoid expensive deepEquals and deepHashCode) - On broker side, store BYTES column using ByteArray instead of String for performance improvement - On broker side, support type compatible merges for all selection queries No format change on the query results. TODO: We are still returning String for BYTES column when preserving the type. Consider changing it to byte[].
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snleee
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Apr 8, 2020
| break; | ||
| default: | ||
| case OBJECT: |
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this is needed for intermediate aggregated object like HLL?
| switch (dataType) { | ||
| // Single-value column | ||
| case INT: | ||
| return ((Number) value).intValue(); |
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From IntermediateResultsBlock class, you kind of directly casted types to an object instead of casting to Number. Can we use the same approach here?
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We are trying to handle compatible types here (commented on line 514). This is required for cases where different segments have different schema (same column name, but different data types).
The long term solution should be let the query engine use the table schema instead of the schema inside each segments.
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In order to support order-by on BYTES column everywhere, inside the system we should always use ByteArray (comparable) to store the BYTES value.
Currently BYTES value are stored as byte[], ByteArray or String in different places, which is very confusing and could cause casting errors.
Changes:
No format change on the query results.
TODO: We are still returning String for BYTES column when preserving the type. Consider changing it to byte[].