Fix bug in tsdb doc value codec #134979
Fix bug in tsdb doc value codec #134979
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The ordinal range encoding doesn't support multi-valued fields, but the logic that prohibits its usage for multi-valued field was missing, which resulted in multi-valued fields being incorrectly encoded. The ordinal range encoding was introduced for primary sort fields only to allow a more efficient look-ahead / skip logic. This is to efficiently determine whether a constant block could be used for a range of matching doc ids in compute engine. Closes elastic#134950
| final RandomAccessInput addressesInput = data.randomAccessSlice(entry.addressesOffset, entry.addressesLength); | ||
| final LongValues addresses = DirectMonotonicReader.getInstance(entry.addressesMeta, addressesInput, merging); | ||
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| assert entry.sortedOrdinals == null : "encoded ordinal range supports only one value per document"; |
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Invoking getValues(...) will result into a NPE if entry.sortedOrdinals != null.
Maybe we can return a singleton SortedNumericDocValues instance here, so that at least the the first value of every document is available?
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Pinging @elastic/es-storage-engine (Team:StorageEngine) |
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@martijnvg Thanks for fixing this - this is the correct solution. However, indexes with multi-valued fields that have already been encoded with ordinal range will remain broken. Should we also support reading them? |
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Thanks Nhat for taking a look.
Yes, I was thinking about this too: #134979 (comment) |
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The ordinal range encoding doesn't support multi-valued fields, but the logic that prohibits its usage for multi-valued field was missing, which resulted in multi-valued fields being incorrectly encoded.
The ordinal range encoding was introduced for primary sort fields only to allow a more efficient look-ahead / skip logic (#133018). This is to more efficiently determine whether a constant block could be used for a range of matching doc ids in compute engine.
Closes #134950
(marking as non-issue as this is a bug doesn't occur in a stateful release)