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7865280399
If the regex compiler can see that a regex is unsatisfiable (for example, '$foo') then it may emit an NFA having no arcs. pg_trgm's packGraph function did the wrong thing in this case; it would access off the end of a work array, and with bad luck could produce a corrupted output data structure causing more problems later. This could end with wrong answers or crashes in queries using a pg_trgm GIN or GiST index with such a regex. Fix by not trying to de-duplicate if there aren't at least 2 arcs. Per bug #17830 from Alexander Lakhin. Back-patch to all supported branches. Discussion: https://postgr.es/m/17830-57ff5f89bdb02b09@postgresql.org
49 lines
2.8 KiB
SQL
49 lines
2.8 KiB
SQL
CREATE TABLE test_trgm2(t text COLLATE "C");
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\copy test_trgm2 from 'data/trgm2.data'
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-- reduce noise
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set extra_float_digits = 0;
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select t,word_similarity('Baykal',t) as sml from test_trgm2 where 'Baykal' <% t order by sml desc, t;
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select t,word_similarity('Kabankala',t) as sml from test_trgm2 where 'Kabankala' <% t order by sml desc, t;
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select t,word_similarity('Baykal',t) as sml from test_trgm2 where t %> 'Baykal' order by sml desc, t;
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select t,word_similarity('Kabankala',t) as sml from test_trgm2 where t %> 'Kabankala' order by sml desc, t;
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select t <->> 'Kabankala', t from test_trgm2 order by t <->> 'Kabankala' limit 7;
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create index trgm_idx2 on test_trgm2 using gist (t gist_trgm_ops);
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set enable_seqscan=off;
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select t,word_similarity('Baykal',t) as sml from test_trgm2 where 'Baykal' <% t order by sml desc, t;
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select t,word_similarity('Kabankala',t) as sml from test_trgm2 where 'Kabankala' <% t order by sml desc, t;
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select t,word_similarity('Baykal',t) as sml from test_trgm2 where t %> 'Baykal' order by sml desc, t;
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select t,word_similarity('Kabankala',t) as sml from test_trgm2 where t %> 'Kabankala' order by sml desc, t;
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explain (costs off)
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select t <->> 'Kabankala', t from test_trgm2 order by t <->> 'Kabankala' limit 7;
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select t <->> 'Kabankala', t from test_trgm2 order by t <->> 'Kabankala' limit 7;
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drop index trgm_idx2;
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create index trgm_idx2 on test_trgm2 using gin (t gin_trgm_ops);
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set enable_seqscan=off;
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select t,word_similarity('Baykal',t) as sml from test_trgm2 where 'Baykal' <% t order by sml desc, t;
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select t,word_similarity('Kabankala',t) as sml from test_trgm2 where 'Kabankala' <% t order by sml desc, t;
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select t,word_similarity('Baykal',t) as sml from test_trgm2 where t %> 'Baykal' order by sml desc, t;
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select t,word_similarity('Kabankala',t) as sml from test_trgm2 where t %> 'Kabankala' order by sml desc, t;
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set "pg_trgm.word_similarity_threshold" to 0.5;
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select t,word_similarity('Baykal',t) as sml from test_trgm2 where 'Baykal' <% t order by sml desc, t;
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select t,word_similarity('Kabankala',t) as sml from test_trgm2 where 'Kabankala' <% t order by sml desc, t;
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select t,word_similarity('Baykal',t) as sml from test_trgm2 where t %> 'Baykal' order by sml desc, t;
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select t,word_similarity('Kabankala',t) as sml from test_trgm2 where t %> 'Kabankala' order by sml desc, t;
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set "pg_trgm.word_similarity_threshold" to 0.3;
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select t,word_similarity('Baykal',t) as sml from test_trgm2 where 'Baykal' <% t order by sml desc, t;
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select t,word_similarity('Kabankala',t) as sml from test_trgm2 where 'Kabankala' <% t order by sml desc, t;
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select t,word_similarity('Baykal',t) as sml from test_trgm2 where t %> 'Baykal' order by sml desc, t;
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select t,word_similarity('Kabankala',t) as sml from test_trgm2 where t %> 'Kabankala' order by sml desc, t;
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-- test unsatisfiable pattern
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select * from test_trgm2 where t ~ '.*$x';
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