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Merge pull request #4 from supabase/or/issue_1
Only consider indexes on primitive types
2 parents 7c0386f + 436451b commit 1aa1016

13 files changed

+363
-9
lines changed

‎index_advisor--0.1.0--0.1.1.sql‎

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drop type index_advisor_output;
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create or replace function index_advisor(
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query text
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)
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returns table (
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startup_cost_before jsonb,
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startup_cost_after jsonb,
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total_cost_before jsonb,
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total_cost_after jsonb,
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index_statements text[]
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)
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volatile
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language plpgsql
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as $$
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declare
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n_args int;
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prepared_statement_name text = 'index_advisor_working_statement';
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hypopg_schema_name text = (select extnamespace::regnamespace::text from pg_extension where extname = 'hypopg');
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explain_plan_statement text;
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rec record;
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plan_initial jsonb;
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plan_final jsonb;
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statements text[] = '{}';
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begin
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-- Disallow multiple statements
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if query ilike '%;%' then
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raise exception 'query must not contain a semicolon';
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end if;
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-- Hack to support PostgREST because the prepared statement for args incorrectly defaults to text
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query := replace(query, 'WITH pgrst_payload AS (SELECT $1 AS json_data)', 'WITH pgrst_payload AS (SELECT $1::json AS json_data)');
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-- Create a prepared statement for the given query
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deallocate all;
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execute format('prepare %I as %s', prepared_statement_name, query);
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-- Detect how many arguments are present in the prepared statement
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n_args = (
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select
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coalesce(array_length(parameter_types, 1), 0)
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from
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pg_prepared_statements
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where
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name = prepared_statement_name
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limit
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1
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);
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-- Create a SQL statement that can be executed to collect the explain plan
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explain_plan_statement = format(
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'set local plan_cache_mode = force_generic_plan; explain (format json) execute %I%s',
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--'explain (format json) execute %I%s',
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prepared_statement_name,
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case
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when n_args = 0 then ''
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else format(
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'(%s)', array_to_string(array_fill('null'::text, array[n_args]), ',')
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)
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end
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);
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-- Store the query plan before any new indexes
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execute explain_plan_statement into plan_initial;
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-- Create possible indexes
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for rec in (
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with extension_regclass as (
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select
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distinct objid as oid
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from
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pg_depend
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where
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deptype = 'e'
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)
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select
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pc.relnamespace::regnamespace::text as schema_name,
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pc.relname as table_name,
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pa.attname as column_name,
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format(
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'select %I.hypopg_create_index($i$create index on %I.%I(%I)$i$)',
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hypopg_schema_name,
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pc.relnamespace::regnamespace::text,
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pc.relname,
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pa.attname
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) hypopg_statement
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from
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pg_catalog.pg_class pc
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join pg_catalog.pg_attribute pa
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on pc.oid = pa.attrelid
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left join extension_regclass er
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on pc.oid = er.oid
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left join pg_index pi
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on pc.oid = pi.indrelid
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and (select array_agg(x) from unnest(pi.indkey) v(x)) = array[pa.attnum]
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and pi.indexprs is null -- ignore expression indexes
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and pi.indpred is null -- ignore partial indexes
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where
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pc.relnamespace::regnamespace::text not in ( -- ignore schema list
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'pg_catalog', 'pg_toast', 'information_schema'
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)
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and er.oid is null -- ignore entities owned by extensions
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and pc.relkind in ('r', 'm') -- regular tables, and materialized views
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and pc.relpersistence = 'p' -- permanent tables (not unlogged or temporary)
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and pa.attnum > 0
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and not pa.attisdropped
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and pi.indrelid is null
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and pa.atttypid in (20,16,1082,1184,1114,701,23,21,700,1083,2950,1700,25,18,1042,1043)
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)
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loop
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-- Create the hypothetical index
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execute rec.hypopg_statement;
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end loop;
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/*
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for rec in select * from hypopg()
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loop
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raise notice '%', rec;
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end loop;
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*/
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-- Create a prepared statement for the given query
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-- The original prepared statement MUST be dropped because its plan is cached
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execute format('deallocate %I', prepared_statement_name);
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execute format('prepare %I as %s', prepared_statement_name, query);
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-- Store the query plan after new indexes
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execute explain_plan_statement into plan_final;
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--raise notice '%', plan_final;
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-- Idenfity referenced indexes in new plan
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execute format(
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'select
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coalesce(array_agg(hypopg_get_indexdef(indexrelid) order by indrelid, indkey::text), $i${}$i$::text[])
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from
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%I.hypopg()
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where
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%s ilike ($i$%%$i$ || indexname || $i$%%$i$)
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',
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hypopg_schema_name,
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quote_literal(plan_final)::text
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) into statements;
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-- Reset all hypothetical indexes
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perform hypopg_reset();
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-- Reset prepared statements
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deallocate all;
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return query values (
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(plan_initial -> 0 -> 'Plan' -> 'Startup Cost'),
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(plan_final -> 0 -> 'Plan' -> 'Startup Cost'),
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(plan_initial -> 0 -> 'Plan' -> 'Total Cost'),
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(plan_final -> 0 -> 'Plan' -> 'Total Cost'),
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statements::text[]
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);
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end;
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$$;

‎index_advisor--0.1.1.sql‎

Lines changed: 159 additions & 0 deletions
Original file line numberDiff line numberDiff line change
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1+
create or replace function index_advisor(
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query text
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)
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returns table (
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startup_cost_before jsonb,
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startup_cost_after jsonb,
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total_cost_before jsonb,
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total_cost_after jsonb,
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index_statements text[]
10+
)
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volatile
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language plpgsql
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as $$
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declare
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n_args int;
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prepared_statement_name text = 'index_advisor_working_statement';
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hypopg_schema_name text = (select extnamespace::regnamespace::text from pg_extension where extname = 'hypopg');
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explain_plan_statement text;
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rec record;
20+
plan_initial jsonb;
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plan_final jsonb;
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statements text[] = '{}';
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begin
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25+
-- Disallow multiple statements
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if query ilike '%;%' then
27+
raise exception 'query must not contain a semicolon';
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end if;
29+
30+
-- Hack to support PostgREST because the prepared statement for args incorrectly defaults to text
31+
query := replace(query, 'WITH pgrst_payload AS (SELECT $1 AS json_data)', 'WITH pgrst_payload AS (SELECT $1::json AS json_data)');
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-- Create a prepared statement for the given query
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deallocate all;
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execute format('prepare %I as %s', prepared_statement_name, query);
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-- Detect how many arguments are present in the prepared statement
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n_args = (
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select
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coalesce(array_length(parameter_types, 1), 0)
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from
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pg_prepared_statements
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where
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name = prepared_statement_name
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limit
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1
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);
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-- Create a SQL statement that can be executed to collect the explain plan
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explain_plan_statement = format(
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'set local plan_cache_mode = force_generic_plan; explain (format json) execute %I%s',
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--'explain (format json) execute %I%s',
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prepared_statement_name,
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case
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when n_args = 0 then ''
56+
else format(
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'(%s)', array_to_string(array_fill('null'::text, array[n_args]), ',')
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)
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end
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);
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-- Store the query plan before any new indexes
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execute explain_plan_statement into plan_initial;
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65+
-- Create possible indexes
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for rec in (
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with extension_regclass as (
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select
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distinct objid as oid
70+
from
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pg_depend
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where
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deptype = 'e'
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)
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select
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pc.relnamespace::regnamespace::text as schema_name,
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pc.relname as table_name,
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pa.attname as column_name,
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format(
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'select %I.hypopg_create_index($i$create index on %I.%I(%I)$i$)',
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hypopg_schema_name,
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pc.relnamespace::regnamespace::text,
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pc.relname,
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pa.attname
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) hypopg_statement
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from
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pg_catalog.pg_class pc
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join pg_catalog.pg_attribute pa
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on pc.oid = pa.attrelid
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left join extension_regclass er
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on pc.oid = er.oid
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left join pg_index pi
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on pc.oid = pi.indrelid
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and (select array_agg(x) from unnest(pi.indkey) v(x)) = array[pa.attnum]
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and pi.indexprs is null -- ignore expression indexes
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and pi.indpred is null -- ignore partial indexes
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where
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pc.relnamespace::regnamespace::text not in ( -- ignore schema list
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'pg_catalog', 'pg_toast', 'information_schema'
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)
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and er.oid is null -- ignore entities owned by extensions
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and pc.relkind in ('r', 'm') -- regular tables, and materialized views
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and pc.relpersistence = 'p' -- permanent tables (not unlogged or temporary)
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and pa.attnum > 0
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and not pa.attisdropped
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and pi.indrelid is null
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and pa.atttypid in (20,16,1082,1184,1114,701,23,21,700,1083,2950,1700,25,18,1042,1043)
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)
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loop
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-- Create the hypothetical index
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execute rec.hypopg_statement;
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end loop;
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/*
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for rec in select * from hypopg()
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loop
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raise notice '%', rec;
118+
end loop;
119+
*/
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121+
-- Create a prepared statement for the given query
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-- The original prepared statement MUST be dropped because its plan is cached
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execute format('deallocate %I', prepared_statement_name);
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execute format('prepare %I as %s', prepared_statement_name, query);
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-- Store the query plan after new indexes
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execute explain_plan_statement into plan_final;
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--raise notice '%', plan_final;
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-- Idenfity referenced indexes in new plan
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execute format(
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'select
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coalesce(array_agg(hypopg_get_indexdef(indexrelid) order by indrelid, indkey::text), $i${}$i$::text[])
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from
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%I.hypopg()
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where
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%s ilike ($i$%%$i$ || indexname || $i$%%$i$)
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',
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hypopg_schema_name,
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quote_literal(plan_final)::text
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) into statements;
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-- Reset all hypothetical indexes
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perform hypopg_reset();
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-- Reset prepared statements
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deallocate all;
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return query values (
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(plan_initial -> 0 -> 'Plan' -> 'Startup Cost'),
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(plan_final -> 0 -> 'Plan' -> 'Startup Cost'),
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(plan_initial -> 0 -> 'Plan' -> 'Total Cost'),
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(plan_final -> 0 -> 'Plan' -> 'Total Cost'),
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statements::text[]
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);
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end;
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$$;

‎index_advisor.control‎

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Original file line numberDiff line numberDiff line change
@@ -1,4 +1,4 @@
11
comment = 'Query index advisor'
2-
default_version = '0.1.0'
2+
default_version = '0.1.1'
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relocatable = true
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requires = hypopg

‎test/expected/disallow_semicolon.out‎

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Original file line numberDiff line numberDiff line change
@@ -1,5 +1,5 @@
11
begin;
2-
create extension index_advisor cascade;
2+
create extension index_advisor version '0.1.1' cascade;
33
NOTICE: installing required extension "hypopg"
44
select index_advisor($$ select 1; $$);
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ERROR: query must not contain a semicolon

‎test/expected/integration.out‎

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Original file line numberDiff line numberDiff line change
@@ -1,5 +1,5 @@
11
begin;
2-
create extension index_advisor cascade;
2+
create extension index_advisor version '0.1.1' cascade;
33
NOTICE: installing required extension "hypopg"
44
create table public.book(
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id int,

‎test/expected/issue_1.out‎

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begin;
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create extension index_advisor version '0.1.1' cascade;
3+
NOTICE: installing required extension "hypopg"
4+
create table public.book(
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id int,
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-- json type is not btree indexable. In version 0.1.1 this raises the error
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-- ERROR: data type json has no default operator class for access method "btree"
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meta json
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);
10+
select index_advisor($$
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select * from book where id = $1
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$$);
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index_advisor
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------------------------------------------------------------------------------
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(0.00,4.07,25.88,13.54,"{""CREATE INDEX ON public.book USING btree (id)""}")
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(1 row)
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18+
rollback;

‎test/expected/multi_index.out‎

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Original file line numberDiff line numberDiff line change
@@ -1,5 +1,5 @@
11
begin;
2-
create extension index_advisor cascade;
2+
create extension index_advisor version '0.1.1' cascade;
33
NOTICE: installing required extension "hypopg"
44
create table author(
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id serial primary key,

‎test/expected/postgrest_query.out‎

Lines changed: 1 addition & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -1,5 +1,5 @@
11
begin;
2-
create extension index_advisor cascade;
2+
create extension index_advisor version '0.1.1' cascade;
33
NOTICE: installing required extension "hypopg"
44
create function get_info(x int) returns text language sql as $$ select 'foo' $$;
55
select index_advisor($$

‎test/sql/disallow_semicolon.sql‎

Lines changed: 1 addition & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -1,6 +1,6 @@
11
begin;
22

3-
create extension index_advisor cascade;
3+
create extension index_advisor version '0.1.1' cascade;
44

55
select index_advisor($$ select 1; $$);
66

‎test/sql/integration.sql‎

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Original file line numberDiff line numberDiff line change
@@ -1,6 +1,6 @@
11
begin;
22

3-
create extension index_advisor cascade;
3+
create extension index_advisor version '0.1.1' cascade;
44

55
create table public.book(
66
id int,

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