Schema-qualify hypopg_reset() and hypopg_get_indexdef() calls

index_advisor--0.2.0--0.2.1.sql

@@ -0,0 +1,191 @@
+create or replace function index_advisor(
+    query text
+)
+    returns table  (
+        startup_cost_before jsonb,
+        startup_cost_after jsonb,
+        total_cost_before jsonb,
+        total_cost_after jsonb,
+        index_statements text[],
+        errors text[]
+    )
+    volatile
+    language plpgsql
+    as $$
+declare
+    n_args int;
+    prepared_statement_name text = 'index_advisor_working_statement';
+    hypopg_schema_name text = (select extnamespace::regnamespace::text from pg_extension where extname = 'hypopg');
+    explain_plan_statement text;
+    error_message text;
+    rec record;
+    plan_initial jsonb;
+    plan_final jsonb;
+    statements text[] = '{}';
+begin
+
+    -- Remove comment lines (its common that they contain semicolons)
+    query := trim(
+        regexp_replace(
+            regexp_replace(
+                regexp_replace(query,'\/\*.+\*\/', '', 'g'),
+            '--[^\r\n]*', ' ', 'g'),
+        '\s+', ' ', 'g')
+    );
+
+    -- Remove trailing semicolon
+    query := regexp_replace(query, ';\s*$', '');
+
+    begin
+        -- Disallow multiple statements
+        if query ilike '%;%' then
+            raise exception 'Query must not contain a semicolon';
+        end if;
+
+        -- Hack to support PostgREST because the prepared statement for args incorrectly defaults to text
+        query := replace(query, 'WITH pgrst_payload AS (SELECT $1 AS json_data)', 'WITH pgrst_payload AS (SELECT $1::json AS json_data)');
+
+        -- Create a prepared statement for the given query
+        deallocate all;
+        execute format('prepare %I as %s', prepared_statement_name, query);
+
+        -- Detect how many arguments are present in the prepared statement
+        n_args = (
+            select
+                coalesce(array_length(parameter_types, 1), 0)
+            from
+                pg_prepared_statements
+            where
+                name = prepared_statement_name
+            limit
+                1
+        );
+
+        -- Create a SQL statement that can be executed to collect the explain plan
+        explain_plan_statement = format(
+            'set local plan_cache_mode = force_generic_plan; explain (format json) execute %I%s',
+            --'explain (format json) execute %I%s',
+            prepared_statement_name,
+            case
+                when n_args = 0 then ''
+                else format(
+                    '(%s)', array_to_string(array_fill('null'::text, array[n_args]), ',')
+                )
+            end
+        );
+
+        -- Store the query plan before any new indexes
+        execute explain_plan_statement into plan_initial;
+
+        -- Create possible indexes
+        for rec in (
+            with extension_regclass as (
+                select
+                    distinct objid as oid
+                from
+                    pg_catalog.pg_depend
+                where
+                    deptype = 'e'
+            )
+            select
+                pc.relnamespace::regnamespace::text as schema_name,
+                pc.relname as table_name,
+                pa.attname as column_name,
+                format(
+                    'select %I.hypopg_create_index($i$create index on %I.%I(%I)$i$)',
+                    hypopg_schema_name,
+                    pc.relnamespace::regnamespace::text,
+                    pc.relname,
+                    pa.attname
+                ) hypopg_statement
+            from
+                pg_catalog.pg_class pc
+                join pg_catalog.pg_attribute pa
+                    on pc.oid = pa.attrelid
+                left join extension_regclass er
+                    on pc.oid = er.oid
+                left join pg_catalog.pg_index pi
+                    on pc.oid = pi.indrelid
+                    and (select array_agg(x) from unnest(pi.indkey) v(x)) = array[pa.attnum]
+                    and pi.indexprs is null -- ignore expression indexes
+                    and pi.indpred is null -- ignore partial indexes
+            where
+                pc.relnamespace::regnamespace::text not in ( -- ignore schema list
+                    'pg_catalog', 'pg_toast', 'information_schema'
+                )
+                and er.oid is null -- ignore entities owned by extensions
+                and pc.relkind in ('r', 'm') -- regular tables, and materialized views
+                and pc.relpersistence = 'p' -- permanent tables (not unlogged or temporary)
+                and pa.attnum > 0
+                and not pa.attisdropped
+                and pi.indrelid is null
+                and pa.atttypid in (20,16,1082,1184,1114,701,23,21,700,1083,2950,1700,25,18,1042,1043)
+            )
+            loop
+                -- Create the hypothetical index
+                execute rec.hypopg_statement;
+            end loop;
+
+        /*
+        for rec in select * from hypopg()
+            loop
+                raise notice '%', rec;
+            end loop;
+        */
+
+        -- Create a prepared statement for the given query
+        -- The original prepared statement MUST be dropped because its plan is cached
+        execute format('deallocate %I', prepared_statement_name);
+        execute format('prepare %I as %s', prepared_statement_name, query);
+
+        -- Store the query plan after new indexes
+        execute explain_plan_statement into plan_final;
+
+        --raise notice '%', plan_final;
+
+        -- Idenfity referenced indexes in new plan
+        execute format(
+            'select
+                coalesce(array_agg(%I.hypopg_get_indexdef(indexrelid) order by indrelid, indkey::text), $i${}$i$::text[])
+            from
+                %I.hypopg()
+            where
+                %s ilike ($i$%%$i$ || indexname || $i$%%$i$)
+            ',
+            hypopg_schema_name,
+            hypopg_schema_name,
+            quote_literal(plan_final)::text
+        ) into statements;
+
+        -- Reset all hypothetical indexes
+        execute format('select %I.hypopg_reset()', hypopg_schema_name);
+
+        -- Reset prepared statements
+        deallocate all;
+
+        return query values (
+            (plan_initial -> 0 -> 'Plan' -> 'Startup Cost'),
+            (plan_final -> 0 -> 'Plan' -> 'Startup Cost'),
+            (plan_initial -> 0 -> 'Plan' -> 'Total Cost'),
+            (plan_final -> 0 -> 'Plan' -> 'Total Cost'),
+            statements::text[],
+            array[]::text[]
+        );
+        return;
+
+    exception when others then
+        get stacked diagnostics error_message = MESSAGE_TEXT;
+
+        return query values (
+            null::jsonb,
+            null::jsonb,
+            null::jsonb,
+            null::jsonb,
+            array[]::text[],
+            array[error_message]::text[]
+        );
+        return;
+    end;
+
+end;
+$$;

index_advisor--0.2.1.sql

@@ -0,0 +1,191 @@
+create or replace function index_advisor(
+    query text
+)
+    returns table  (
+        startup_cost_before jsonb,
+        startup_cost_after jsonb,
+        total_cost_before jsonb,
+        total_cost_after jsonb,
+        index_statements text[],
+        errors text[]
+    )
+    volatile
+    language plpgsql
+    as $$
+declare
+    n_args int;
+    prepared_statement_name text = 'index_advisor_working_statement';
+    hypopg_schema_name text = (select extnamespace::regnamespace::text from pg_extension where extname = 'hypopg');
+    explain_plan_statement text;
+    error_message text;
+    rec record;
+    plan_initial jsonb;
+    plan_final jsonb;
+    statements text[] = '{}';
+begin
+
+    -- Remove comment lines (its common that they contain semicolons)
+    query := trim(
+        regexp_replace(
+            regexp_replace(
+                regexp_replace(query,'\/\*.+\*\/', '', 'g'),
+            '--[^\r\n]*', ' ', 'g'),
+        '\s+', ' ', 'g')
+    );
+
+    -- Remove trailing semicolon
+    query := regexp_replace(query, ';\s*$', '');
+
+    begin
+        -- Disallow multiple statements
+        if query ilike '%;%' then
+            raise exception 'Query must not contain a semicolon';
+        end if;
+
+        -- Hack to support PostgREST because the prepared statement for args incorrectly defaults to text
+        query := replace(query, 'WITH pgrst_payload AS (SELECT $1 AS json_data)', 'WITH pgrst_payload AS (SELECT $1::json AS json_data)');
+
+        -- Create a prepared statement for the given query
+        deallocate all;
+        execute format('prepare %I as %s', prepared_statement_name, query);
+
+        -- Detect how many arguments are present in the prepared statement
+        n_args = (
+            select
+                coalesce(array_length(parameter_types, 1), 0)
+            from
+                pg_prepared_statements
+            where
+                name = prepared_statement_name
+            limit
+                1
+        );
+
+        -- Create a SQL statement that can be executed to collect the explain plan
+        explain_plan_statement = format(
+            'set local plan_cache_mode = force_generic_plan; explain (format json) execute %I%s',
+            --'explain (format json) execute %I%s',
+            prepared_statement_name,
+            case
+                when n_args = 0 then ''
+                else format(
+                    '(%s)', array_to_string(array_fill('null'::text, array[n_args]), ',')
+                )
+            end
+        );
+
+        -- Store the query plan before any new indexes
+        execute explain_plan_statement into plan_initial;
+
+        -- Create possible indexes
+        for rec in (
+            with extension_regclass as (
+                select
+                    distinct objid as oid
+                from
+                    pg_catalog.pg_depend
+                where
+                    deptype = 'e'
+            )
+            select
+                pc.relnamespace::regnamespace::text as schema_name,
+                pc.relname as table_name,
+                pa.attname as column_name,
+                format(
+                    'select %I.hypopg_create_index($i$create index on %I.%I(%I)$i$)',
+                    hypopg_schema_name,
+                    pc.relnamespace::regnamespace::text,
+                    pc.relname,
+                    pa.attname
+                ) hypopg_statement
+            from
+                pg_catalog.pg_class pc
+                join pg_catalog.pg_attribute pa
+                    on pc.oid = pa.attrelid
+                left join extension_regclass er
+                    on pc.oid = er.oid
+                left join pg_catalog.pg_index pi
+                    on pc.oid = pi.indrelid
+                    and (select array_agg(x) from unnest(pi.indkey) v(x)) = array[pa.attnum]
+                    and pi.indexprs is null -- ignore expression indexes
+                    and pi.indpred is null -- ignore partial indexes
+            where
+                pc.relnamespace::regnamespace::text not in ( -- ignore schema list
+                    'pg_catalog', 'pg_toast', 'information_schema'
+                )
+                and er.oid is null -- ignore entities owned by extensions
+                and pc.relkind in ('r', 'm') -- regular tables, and materialized views
+                and pc.relpersistence = 'p' -- permanent tables (not unlogged or temporary)
+                and pa.attnum > 0
+                and not pa.attisdropped
+                and pi.indrelid is null
+                and pa.atttypid in (20,16,1082,1184,1114,701,23,21,700,1083,2950,1700,25,18,1042,1043)
+            )
+            loop
+                -- Create the hypothetical index
+                execute rec.hypopg_statement;
+            end loop;
+
+        /*
+        for rec in select * from hypopg()
+            loop
+                raise notice '%', rec;
+            end loop;
+        */
+
+        -- Create a prepared statement for the given query
+        -- The original prepared statement MUST be dropped because its plan is cached
+        execute format('deallocate %I', prepared_statement_name);
+        execute format('prepare %I as %s', prepared_statement_name, query);
+
+        -- Store the query plan after new indexes
+        execute explain_plan_statement into plan_final;
+
+        --raise notice '%', plan_final;
+
+        -- Idenfity referenced indexes in new plan
+        execute format(
+            'select
+                coalesce(array_agg(%I.hypopg_get_indexdef(indexrelid) order by indrelid, indkey::text), $i${}$i$::text[])
+            from
+                %I.hypopg()
+            where
+                %s ilike ($i$%%$i$ || indexname || $i$%%$i$)
+            ',
+            hypopg_schema_name,
+            hypopg_schema_name,
+            quote_literal(plan_final)::text
+        ) into statements;
+
+        -- Reset all hypothetical indexes
+        execute format('select %I.hypopg_reset()', hypopg_schema_name);
+
+        -- Reset prepared statements
+        deallocate all;
+
+        return query values (
+            (plan_initial -> 0 -> 'Plan' -> 'Startup Cost'),
+            (plan_final -> 0 -> 'Plan' -> 'Startup Cost'),
+            (plan_initial -> 0 -> 'Plan' -> 'Total Cost'),
+            (plan_final -> 0 -> 'Plan' -> 'Total Cost'),
+            statements::text[],
+            array[]::text[]
+        );
+        return;
+
+    exception when others then
+        get stacked diagnostics error_message = MESSAGE_TEXT;
+
+        return query values (
+            null::jsonb,
+            null::jsonb,
+            null::jsonb,
+            null::jsonb,
+            array[]::text[],
+            array[error_message]::text[]
+        );
+        return;
+    end;
+
+end;
+$$;

index_advisor.control

@@ -1,4 +1,4 @@
 comment = 'Query index advisor'
-default_version = '0.2.0'
+default_version = '0.2.1'
 relocatable = true
 requires = hypopg