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This commit implements page filtering based on the Parquet page index. The read and evaluation of the page index is done by the HdfsParquetScanner. At first, we determine the row ranges we are interested in, and based on the row ranges we determine the candidate pages for each column that we are reading. We still issue one ScanRange per column chunk, but we specify sub-ranges that store the candidate pages, i.e. we don't read the whole column chunk, but only fractions of it. Pages are not aligned across column chunks, i.e. page #2 of column A might store completely different rows than page #2 of column B. It means we need to implement some kind of row-skipping logic when we read the data pages. This logic is implemented in BaseScalarColumnReader and ScalarColumnReader. Collection column readers know nothing about page filtering. Page filtering can be turned off by setting the query option 'read_parquet_page_index' to false. Testing: * added some unit tests for the row range and page selection logic * generated various Parquet files with Parquet-MR * enabled Page index writing and wrote selective queries against tables written by Impala. Current tests are likely to use page filtering transparently. Performance: * Measured locally, observed 3x to 20x speedup for selective queries. The speedup was proportional to the IO operations need to be done. * The TPCH benchmark didn't show a significant performance change. It is not a suprise since the data is not being sorted in any useful way. So the main goal was to not introduce perf regression. TODO: * measure performance for remote reads Change-Id: I0cc99f129f2048dbafbe7f5a51d1ea3a5005731a Reviewed-on: http://gerrit.cloudera.org:8080/12065 Reviewed-by: Impala Public Jenkins <impala-public-jenkins@cloudera.com> Tested-by: Impala Public Jenkins <impala-public-jenkins@cloudera.com>
211 lines
8.4 KiB
Plaintext
211 lines
8.4 KiB
Plaintext
====
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---- QUERY
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# This test relies on a deterministic row order so we use "sort by (id)".
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create table alltypes sort by (id) like functional_parquet.alltypes;
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alter table alltypes set tblproperties("impala.enable.stats.extrapolation"="true");
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insert into alltypes partition(year, month)
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select * from functional_parquet.alltypes where year = 2009;
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====
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---- QUERY
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# No stats are available.
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explain select id from alltypes;
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---- RESULTS: VERIFY_IS_SUBSET
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' stored statistics:'
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' table: rows=unavailable size=unavailable'
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' partitions: 0/12 rows=unavailable'
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' columns: unavailable'
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row_regex:.* extrapolated-rows=unavailable.*
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' tuple-ids=0 row-size=4B cardinality=unavailable'
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---- TYPES
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STRING
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====
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---- QUERY
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compute stats alltypes
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---- RESULTS
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'Updated 1 partition(s) and 11 column(s).'
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---- TYPES
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STRING
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====
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---- QUERY
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# Only the table-level row count is stored. The partition row counts are extrapolated.
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show table stats alltypes
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---- LABELS
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YEAR, MONTH, #ROWS, EXTRAP #ROWS, #FILES, SIZE, BYTES CACHED, CACHE REPLICATION, FORMAT, INCREMENTAL STATS, LOCATION
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---- RESULTS
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'2009','1',-1,308,1,regex:.*B,'NOT CACHED','NOT CACHED','PARQUET','false','$NAMENODE/test-warehouse/$DATABASE.db/alltypes/year=2009/month=1'
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'2009','2',-1,289,1,regex:.*B,'NOT CACHED','NOT CACHED','PARQUET','false','$NAMENODE/test-warehouse/$DATABASE.db/alltypes/year=2009/month=2'
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'2009','3',-1,307,1,regex:.*B,'NOT CACHED','NOT CACHED','PARQUET','false','$NAMENODE/test-warehouse/$DATABASE.db/alltypes/year=2009/month=3'
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'2009','4',-1,302,1,regex:.*B,'NOT CACHED','NOT CACHED','PARQUET','false','$NAMENODE/test-warehouse/$DATABASE.db/alltypes/year=2009/month=4'
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'2009','5',-1,307,1,regex:.*B,'NOT CACHED','NOT CACHED','PARQUET','false','$NAMENODE/test-warehouse/$DATABASE.db/alltypes/year=2009/month=5'
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'2009','6',-1,302,1,regex:.*B,'NOT CACHED','NOT CACHED','PARQUET','false','$NAMENODE/test-warehouse/$DATABASE.db/alltypes/year=2009/month=6'
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'2009','7',-1,307,1,regex:.*B,'NOT CACHED','NOT CACHED','PARQUET','false','$NAMENODE/test-warehouse/$DATABASE.db/alltypes/year=2009/month=7'
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'2009','8',-1,307,1,regex:.*B,'NOT CACHED','NOT CACHED','PARQUET','false','$NAMENODE/test-warehouse/$DATABASE.db/alltypes/year=2009/month=8'
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'2009','9',-1,302,1,regex:.*B,'NOT CACHED','NOT CACHED','PARQUET','false','$NAMENODE/test-warehouse/$DATABASE.db/alltypes/year=2009/month=9'
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'2009','10',-1,307,1,regex:.*B,'NOT CACHED','NOT CACHED','PARQUET','false','$NAMENODE/test-warehouse/$DATABASE.db/alltypes/year=2009/month=10'
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'2009','11',-1,302,1,regex:.*B,'NOT CACHED','NOT CACHED','PARQUET','false','$NAMENODE/test-warehouse/$DATABASE.db/alltypes/year=2009/month=11'
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'2009','12',-1,307,1,regex:.*B,'NOT CACHED','NOT CACHED','PARQUET','false','$NAMENODE/test-warehouse/$DATABASE.db/alltypes/year=2009/month=12'
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'Total','',3650,3650,12,regex:.*B,'0B','','','',''
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---- TYPES
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STRING,STRING,BIGINT,BIGINT,BIGINT,STRING,STRING,STRING,STRING,STRING,STRING
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====
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---- QUERY
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# Stats are available now.
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explain select id from alltypes;
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---- RESULTS: VERIFY_IS_EQUAL
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row_regex:.*Max Per-Host Resource Reservation: Memory=.*
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row_regex:.*Per-Host Resource Estimates: Memory=.*
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'Codegen disabled by planner'
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row_regex:.*Analyzed query: SELECT id FROM test_stats_extrapolation_.*.alltypes.*
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''
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'F00:PLAN FRAGMENT [UNPARTITIONED] hosts=1 instances=1'
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row_regex:.*Per-Host Resources: mem-estimate=.* mem-reservation=.*
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'PLAN-ROOT SINK'
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row_regex:.*mem-estimate=.* mem-reservation=.*
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'|'
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'00:SCAN $FILESYSTEM_NAME [$DATABASE.alltypes]'
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row_regex:.*partitions=12/12 files=12 size=.*
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' stored statistics:'
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row_regex:.*table: rows=3.65K size=.*
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' partitions: 0/12 rows=unavailable'
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' columns: all'
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row_regex:.* extrapolated-rows=3.65K .*
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row_regex:.*mem-estimate=.* mem-reservation=.*
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' tuple-ids=0 row-size=4B cardinality=3.65K'
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' in pipelines: 00(GETNEXT)'
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---- TYPES
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STRING
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====
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---- QUERY
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# Select a subset of partitions.
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explain select id from alltypes where month in (1, 2, 3);
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---- RESULTS: VERIFY_IS_EQUAL
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row_regex:.*Max Per-Host Resource Reservation: Memory=.*
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row_regex:.*Per-Host Resource Estimates: Memory=.*
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'Codegen disabled by planner'
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row_regex:.*Analyzed query: SELECT id FROM test_stats_extrapolation_.*.alltypes WHERE.*
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'`month` IN (CAST(1 AS INT), CAST(2 AS INT), CAST(3 AS INT))'
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''
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'F00:PLAN FRAGMENT [UNPARTITIONED] hosts=1 instances=1'
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row_regex:.*mem-estimate=.* mem-reservation=.*
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'PLAN-ROOT SINK'
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row_regex:.*mem-estimate=.* mem-reservation=.*
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'|'
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'00:SCAN $FILESYSTEM_NAME [$DATABASE.alltypes]'
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' partition predicates: `month` IN (CAST(1 AS INT), CAST(2 AS INT), CAST(3 AS INT))'
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row_regex:.*partitions=3/12 files=3 size=.*
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' stored statistics:'
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row_regex:.*table: rows=3.65K size=.*
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' partitions: 0/3 rows=unavailable'
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' columns: all'
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row_regex:.* extrapolated-rows=904.*
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row_regex:.*mem-estimate=.* mem-reservation=.*
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' tuple-ids=0 row-size=4B cardinality=904'
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' in pipelines: 00(GETNEXT)'
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---- TYPES
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STRING
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====
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---- QUERY
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# Double the data in existing partitions.
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insert into alltypes partition(year, month)
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select * from functional_parquet.alltypes where year = 2009;
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explain select id from alltypes;
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---- RESULTS: VERIFY_IS_EQUAL
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row_regex:.*Max Per-Host Resource Reservation: Memory=.*
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row_regex:.*Per-Host Resource Estimates: Memory=.*
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row_regex:.*Analyzed query: SELECT id FROM test_stats_extrapolation_.*.alltypes.*
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''
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'F00:PLAN FRAGMENT [UNPARTITIONED] hosts=1 instances=1'
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row_regex:.*Per-Host Resources: mem-estimate=.* mem-reservation=.*
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'PLAN-ROOT SINK'
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row_regex:.*mem-estimate=.* mem-reservation=.*
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'|'
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'00:SCAN $FILESYSTEM_NAME [$DATABASE.alltypes]'
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row_regex:.*partitions=12/12 files=24 size=.*
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' stored statistics:'
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row_regex:.*table: rows=3.65K size=.*
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' partitions: 0/12 rows=unavailable'
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' columns: all'
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row_regex:.* extrapolated-rows=7.30K .*
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row_regex:.*mem-estimate=.* mem-reservation=.*
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' tuple-ids=0 row-size=4B cardinality=7.30K'
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' in pipelines: 00(GETNEXT)'
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---- TYPES
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STRING
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====
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---- QUERY
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# Create new partitions and extrapolate their row count.
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insert into alltypes partition(year, month)
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select * from functional_parquet.alltypes where year = 2010;
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explain select id from alltypes where year = 2010;
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---- RESULTS: VERIFY_IS_EQUAL
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row_regex:.*Max Per-Host Resource Reservation: Memory=.*
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row_regex:.*Per-Host Resource Estimates: Memory=16MB.*
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'Codegen disabled by planner'
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row_regex:.*Analyzed query: SELECT id FROM test_stats_extrapolation_.*.alltypes WHERE.*
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'`year` = CAST(2010 AS INT)'
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''
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'F00:PLAN FRAGMENT [UNPARTITIONED] hosts=1 instances=1'
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row_regex:.*Per-Host Resources: mem-estimate=.* mem-reservation=.*
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'PLAN-ROOT SINK'
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row_regex:.*mem-estimate=.* mem-reservation=.*
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'|'
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'00:SCAN $FILESYSTEM_NAME [$DATABASE.alltypes]'
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' partition predicates: `year` = CAST(2010 AS INT)'
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row_regex:.*partitions=12/24 files=12 size=.*
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' stored statistics:'
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row_regex:.*table: rows=3.65K size=.*
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' partitions: 0/12 rows=unavailable'
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' columns: all'
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row_regex:.* extrapolated-rows=3.65K .*
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row_regex:.*mem-estimate=.* mem-reservation=.*
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' tuple-ids=0 row-size=4B cardinality=3.65K'
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' in pipelines: 00(GETNEXT)'
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---- TYPES
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STRING
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====
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---- QUERY
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# Compute stats and run the same query again.
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compute stats alltypes;
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explain select id from alltypes where year = 2010;
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---- RESULTS: VERIFY_IS_EQUAL
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row_regex:.*Max Per-Host Resource Reservation: Memory=.*
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row_regex:.*Per-Host Resource Estimates: Memory=16MB.*
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'Codegen disabled by planner'
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row_regex:.*Analyzed query: SELECT id FROM test_stats_extrapolation_.*.alltypes WHERE.*
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'`year` = CAST(2010 AS INT)'
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''
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'F00:PLAN FRAGMENT [UNPARTITIONED] hosts=1 instances=1'
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row_regex:.*Per-Host Resources: mem-estimate=.* mem-reservation=.*
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'PLAN-ROOT SINK'
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row_regex:.*mem-estimate=.* mem-reservation=.*
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'|'
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'00:SCAN $FILESYSTEM_NAME [$DATABASE.alltypes]'
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' partition predicates: `year` = CAST(2010 AS INT)'
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row_regex:.*partitions=12/24 files=12 size=.*
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' stored statistics:'
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row_regex:.*table: rows=10.95K size=.*
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' partitions: 0/12 rows=unavailable'
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' columns: all'
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row_regex:.* extrapolated-rows=3.65K .*
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row_regex:.*mem-estimate=.* mem-reservation=.*
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' tuple-ids=0 row-size=4B cardinality=3.65K'
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' in pipelines: 00(GETNEXT)'
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---- TYPES
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STRING
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====
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---- QUERY
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# Test that dropping stats resets everything.
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drop stats alltypes;
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explain select id from alltypes;
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---- RESULTS: VERIFY_IS_SUBSET
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' stored statistics:'
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' table: rows=unavailable size=unavailable'
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' partitions: 0/24 rows=unavailable'
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' columns: unavailable'
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row_regex:.* extrapolated-rows=unavailable.*
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' tuple-ids=0 row-size=4B cardinality=unavailable'
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' in pipelines: 00(GETNEXT)'
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---- TYPES
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STRING
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====
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