Commit
This commit does not belong to any branch on this repository, and may belong to a fork outside of the repository.
Merge pull request #6 from supabase/or/issue_2
Error handling
- Loading branch information
Showing
18 changed files
with
486 additions
and
82 deletions.
There are no files selected for viewing
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Original file line number | Diff line number | Diff line change |
---|---|---|
@@ -0,0 +1,168 @@ | ||
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[] | ||
) | ||
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; | ||
rec record; | ||
plan_initial jsonb; | ||
plan_final jsonb; | ||
statements text[] = '{}'; | ||
begin | ||
|
||
-- Remove comment lines if they contain a semicolon (this is common is queries through supabase.js) | ||
query := trim( | ||
regexp_replace( | ||
regexp_replace( | ||
regexp_replace(query,'\/\*.+\*\/', '', 'g'), | ||
'--[^\r\n]*', ' ', 'g'), | ||
'\s+', ' ', 'g') | ||
); | ||
|
||
-- 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_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_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(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, | ||
quote_literal(plan_final)::text | ||
) into statements; | ||
|
||
-- Reset all hypothetical indexes | ||
perform hypopg_reset(); | ||
|
||
-- 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[] | ||
); | ||
|
||
end; | ||
$$; |
Oops, something went wrong.