Special query plan step for read from MergeTree #22352
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| selectPartsToRead(parts, part_values, minmax_idx_condition, minmax_columns_types, partition_pruner, max_block_numbers_to_read); | ||
| selectPartsToRead(parts, part_values, minmax_idx_condition, minmax_columns_types, partition_pruner, max_block_numbers_to_read, part_filter_counters); | ||
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| index_stats->emplace_back(ReadFromMergeTree::IndexStat{ |
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Maybe we can avoid printing it if we have at least one index condition?
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I think it is useful to add.
We can see how indexes drop parts and granules.
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alesapin
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Apr 14, 2021
| Name: t_minmax | ||
| Parts: 1 | ||
| Granules: 2 | ||
| Skip |
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I see Indexes header, but this Skip looks slightly confusing. Don't have any ideas on how to improve naming here. Maybe we can use something like Skip (minmax) or Skip (set)?
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Ok, I will add it
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Hm, also it may be confusing cause I grep out the description.
It will be minmax GRANULARITY 2
alesapin
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Apr 14, 2021
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| /// This step is created to read from MergeTree* table. | ||
| /// For now, it takes a list of parts and creates source from it. | ||
| class ReadFromMergeTree : public ISourceStep |
alesapin
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Apr 14, 2021
| InReverseOrder, | ||
| }; | ||
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| explicit ReadFromMergeTree( |
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Functional stateless tests (release, wide parts enabled) that's unusual |
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Internal documentation ticket: DOCSUP-8737. |
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Changelog entry (a user-readable short description of the changes that goes to CHANGELOG.md):
Add setting
indexes(boolean, disabled by default) toEXPLAIN PIPELINEquery. When enabled, shows used indexes, number of filtered parts and granules for every index applied. Supported forMergeTree*tables.