From 8ac3d209bb21d440576a705600b5bf92ba414fa4 Mon Sep 17 00:00:00 2001 From: glyn Date: Sat, 29 Aug 2015 21:19:11 +0100 Subject: [PATCH] Initial commit --- .gitignore | 5 + Makefile | 7 + README.md | 15 + sql/table_log_pl--0.1.sql | 419 ++++++++++++++++++++++++++ sql/table_log_pl--unpackaged--0.1.sql | 8 + sql/table_log_pl.sql | 379 +++++++++++++++++++++++ sql/table_log_pl_init.sql | 83 +++++ sql/uninstall_table_log_pl.sql | 12 + table_log_pl.control | 3 + 9 files changed, 931 insertions(+) create mode 100644 .gitignore create mode 100644 Makefile create mode 100644 README.md create mode 100644 sql/table_log_pl--0.1.sql create mode 100644 sql/table_log_pl--unpackaged--0.1.sql create mode 100644 sql/table_log_pl.sql create mode 100644 sql/table_log_pl_init.sql create mode 100644 sql/uninstall_table_log_pl.sql create mode 100644 table_log_pl.control diff --git a/.gitignore b/.gitignore new file mode 100644 index 0000000..d6e9445 --- /dev/null +++ b/.gitignore @@ -0,0 +1,5 @@ +.DS_Store +Thumbs.db +regression.diffs +regression.out +results/ diff --git a/Makefile b/Makefile new file mode 100644 index 0000000..0212d5a --- /dev/null +++ b/Makefile @@ -0,0 +1,7 @@ +EXTENSION = table_log_pl +DATA = $(wildcard sql/*--*.sql) +DOCS = README.md + +PG_CONFIG = pg_config +PGXS := $(shell $(PG_CONFIG) --pgxs) +include $(PGXS) diff --git a/README.md b/README.md new file mode 100644 index 0000000..b3de47b --- /dev/null +++ b/README.md @@ -0,0 +1,15 @@ +table_log_pl +=========== + +Attempt at pl/pgsql drop-in replacement for te dated table_log C extenstion +AKA pg Table Audit / PostgreSQL Table Log / tablelog by Andreas Scherbaum: + http://www.postgresql.org/ftp/projects/pgFoundry/tablelog/tablelog/ + http://github.com/andreasscherbaum/table_log + +A slightly more up to date version of the original C extension can also +be found here: + https://github.com/glynastill/pg_table_audit + +There are now many better ways to audit DML, using json types or advanced +extensions like pgaudit (below), however if for some reason you're stuck +with table_log this may help. diff --git a/sql/table_log_pl--0.1.sql b/sql/table_log_pl--0.1.sql new file mode 100644 index 0000000..4d873b6 --- /dev/null +++ b/sql/table_log_pl--0.1.sql @@ -0,0 +1,419 @@ +-- +-- Glyn Astill 28/08/2015 +-- +-- Attempt at pl/pgsql drop-in replacement for table_log C extenstion AKA +-- pg Table Audit / PostgreSQL Table Log / tablelog by Andreas Scherbaum +-- http://www.postgresql.org/ftp/projects/pgFoundry/tablelog/tablelog/ +-- http://github.com/andreasscherbaum/table_log +-- +-- A slightly more up to date version of the original C extension can +-- also be found here: +-- https://github.com/glynastill/pg_table_audit +-- +-- There are now many better ways to audit DML, using json types or +-- advanced extensions like pgaudit (below), however if for some reason +-- you're stuck with table_log this may help. +-- +-- http://8kb.co.uk/blog/2015/01/19/copying-pavel-stehules-simple-history-table-but-with-the-jsonb-type/ +-- https://github.com/2ndQuadrant/pgaudit + +-- complain if script is sourced in psql, rather than via CREATE EXTENSION +\echo Use "CREATE EXTENSION table_log_pl" to load this file. \quit + +-- + +CREATE OR REPLACE FUNCTION table_log_pl() RETURNS TRIGGER AS +$BODY$ +DECLARE + v_tabname text; + v_loguser boolean := false; + v_nspname text; + v_num_col int; + v_num_col_log int; + v_col_trig text := ''; + v_val_trig text := ''; + v_cols text := ''; + v_sql text; + v_col_cache text; + v_max_cache int; + v_enable_cache boolean := true; +BEGIN + -- Notes: + -- - The trigger_id comes off sequence, this function is oblivious + -- - 3 columns means don't log trigger_user or trigger_id + -- - 4 columns means don't log trigger_user + -- - 5 columns means log both + -- - To use the column data caching on server versions prior to + -- 9.6 add custom var "table_log.column_cache = ''" to postgresql.conf + + IF (TG_NARGS > 2) THEN + v_nspname := TG_ARGV[2]; + ELSE + v_nspname := TG_TABLE_SCHEMA; + END IF; + + IF (TG_NARGS > 1 AND TG_ARGV[1]::int = 1) THEN + v_loguser := true; + END IF; + + IF (TG_NARGS > 0) THEN + v_tabname := TG_ARGV[0]; + ELSE + v_tabname := TG_TABLE_NAME || '_log'; + END IF; + + -- Retrieve custom variable used as a poor mans cache for multirow statements + IF (v_enable_cache) THEN + IF (current_setting('server_version_num')::int >= 90600) THEN + v_col_cache := current_setting('table_log.column_cache', true); + ELSE + v_col_cache := current_setting('table_log.column_cache'); + END IF; + END IF; + + IF (v_enable_cache AND left(v_col_cache, length(TG_RELID::text)+1) = (TG_RELID::text || ':')) THEN + v_cols := right(v_col_cache, (length(TG_RELID::text)+1)*-1); + ELSE + IF (TG_WHEN != 'AFTER') THEN + RAISE EXCEPTION 'table_log: must be fired after event'; + END IF; + IF (TG_LEVEL = 'STATEMENT') THEN + RAISE EXCEPTION 'table_log: can''t process STATEMENT events'; + END IF; + + SELECT count(*), string_agg(quote_ident(attname),',') INTO STRICT v_num_col, v_cols + FROM pg_catalog.pg_attribute + WHERE attrelid = TG_RELID + AND attnum > 0 + AND NOT attisdropped; + + IF (v_num_col < 1) THEN + RAISE EXCEPTION 'table_log: number of columns in table is < 1, can this happen?'; + END IF; + + SELECT count(*) INTO STRICT v_num_col_log + FROM pg_catalog.pg_attribute + WHERE attrelid = (v_nspname || '.' || v_tabname)::regclass + AND attnum > 0 + AND NOT attisdropped; + + IF (v_num_col_log < 1) THEN + RAISE EXCEPTION 'could not get number columns in relation %.%', v_nspname, v_tabname; + END IF; + + -- This is the way the original checks column count regardless of trigger_id is presence + IF (v_num_col_log != (v_num_col + 3 + v_loguser::int)) AND (v_num_col_log != (v_num_col + 4 + v_loguser::int)) THEN + RAISE EXCEPTION 'number colums in relation %.%(%) does not match columns in %.%(%)', TG_TABLE_SCHEMA, TG_TABLE_NAME, v_num_col, v_nspname, v_tabname, v_num_col_log; + END IF; + + -- Set custom variable for use as a poor mans cache for multirow statements + IF (v_enable_cache) THEN + v_col_cache := (TG_RELID::text || ':' || v_cols); + PERFORM set_config('table_log.column_cache', v_col_cache, true); + END IF; + END IF; + + IF (v_loguser) THEN + v_col_trig := v_col_trig || ', "trigger_user"'; + v_val_trig := format('%L, ', session_user); + END IF; + v_col_trig := v_col_trig || ', "trigger_mode", "trigger_changed", "trigger_tuple"'; + v_val_trig := format('%s%L, %L', v_val_trig, TG_OP, current_timestamp); + + IF (TG_OP != 'INSERT') THEN + v_sql := format('INSERT INTO %I.%I (%s%s) SELECT %s, %s, ''old'' FROM (SELECT ($1::text::%I).*) t', v_nspname, v_tabname, v_cols, v_col_trig, v_cols, v_val_trig, TG_RELID::regclass); + EXECUTE v_sql USING OLD; + END IF; + IF (TG_OP != 'DELETE') THEN + v_sql := format('INSERT INTO %I.%I (%s%s) SELECT %s, %s, ''new'' FROM (SELECT ($1::text::%I).*) t', v_nspname, v_tabname, v_cols, v_col_trig, v_cols, v_val_trig, TG_RELID::regclass); + EXECUTE v_sql USING NEW; + RETURN NEW; + ELSE + RETURN OLD; + END IF; + +END; +$BODY$ +LANGUAGE plpgsql VOLATILE; + +-- + +CREATE OR REPLACE FUNCTION table_log_pl_restore_table (origtab varchar, origtab_pk varchar, logtab char, logtab_pk char, restoretab char, to_timestamp timestamptz, search_pk char DEFAULT NULL, method int DEFAULT 0, not_temporarly int DEFAULT 0, origtab_schema varchar DEFAULT NULL, logtab_schema varchar DEFAULT NULL) RETURNS varchar AS +$BODY$ +DECLARE + v_origtab_cols int; + v_logtab_cols int; + v_restoretab_cols int; + v_origtab_fqn text; + v_logtab_fqn text; + v_sql text; + v_cols text; + v_pk_count int; + v_rec record; + v_old_pk_str text; +BEGIN + + -- Notes: + -- + -- The original implimentation doesn't allow fully qualified table + -- references in table_log_restore_table; You can get some milage + -- out of search_path if required there. For this reason the plpgsql + -- version adds the following two optional parameters to those below: + -- + -- - original table schema + -- - logging table schema + -- + -- Comments from C implimentation: + -- + -- restore a complete table based on the logging table + -- + -- parameter: + -- - original table name + -- - name of primary key in original table + -- - logging table + -- - name of primary key in logging table + -- - restore table name + -- - timestamp for restoring data + -- - primary key to restore (only this key will be restored) (optional) + -- - restore mode + -- 0: restore from blank table (default) + -- needs a complete logging table + -- 1: restore from actual table backwards + -- - dont create table temporarly + -- 0: create restore table temporarly (default) + -- 1: create restore table not temporarly + -- return: + -- not yet defined + + IF origtab IS NULL THEN + RAISE NOTICE 'table_log_restore_table: missing original table name'; + END IF; + IF origtab_pk IS NULL THEN + RAISE NOTICE 'table_log_restore_table: missing primary key name for original table'; + END IF; + IF logtab IS NULL THEN + RAISE NOTICE 'table_log_restore_table: missing log table name'; + END IF; + IF logtab_pk IS NULL THEN + RAISE NOTICE 'table_log_restore_table: missing primary key name for log table'; + END IF; + IF restoretab IS NULL THEN + RAISE NOTICE 'table_log_restore_table: missing copy table name'; + END IF; + IF to_timestamp IS NULL THEN + RAISE NOTICE 'table_log_restore_table: missing timestamp'; + END IF; + IF (search_pk IS NOT NULL) THEN + RAISE NOTICE 'table_log_restore_table: will restore a single key'; + END IF; + + IF origtab_pk = logtab_pk THEN + RAISE EXCEPTION 'pkey of logging table cannot be the pkey of the original table: % <-> %', origtab_pk, logtab_pk; + END IF; + + v_origtab_fqn := coalesce(quote_ident(origtab_schema) || '.','') || quote_ident(origtab); + v_logtab_fqn := coalesce(quote_ident(logtab_schema) || '.','') || quote_ident(logtab); + + -- Check original table and get column list + SELECT string_agg(quote_ident(attname), ','), count(*), count(*) filter (where attname=origtab_pk) + INTO v_cols, v_origtab_cols, v_pk_count + FROM pg_catalog.pg_class c + JOIN pg_catalog.pg_attribute a ON a.attrelid = c.oid + JOIN pg_catalog.pg_namespace n ON c.relnamespace = n.oid + WHERE c.relname = origtab AND c.relkind='r' AND a.attnum > 0 + AND (origtab_schema IS NULL OR n.nspname = origtab_schema) + AND NOT attisdropped; + + IF v_origtab_cols = 0 OR v_cols IS NULL THEN + RAISE EXCEPTION 'could not check relation: % (columns = %)', v_origtab_fqn, v_origtab_cols; + ELSIF v_pk_count != 1 THEN + RAISE EXCEPTION 'could not check relation: (missing pkey) % in table %', origtab_pk, v_origtab_fqn; + ELSE + RAISE NOTICE 'original table: OK (% columns)', v_origtab_cols; + END IF; + + -- Check log table + SELECT count(*), count(*) filter (where attname=logtab_pk) + INTO v_logtab_cols, v_pk_count + FROM pg_catalog.pg_class c + JOIN pg_catalog.pg_attribute a ON a.attrelid = c.oid + JOIN pg_catalog.pg_namespace n ON c.relnamespace = n.oid + WHERE c.relname = logtab AND c.relkind='r' AND a.attnum > 0 + AND (logtab_schema IS NULL OR n.nspname = logtab_schema) + AND NOT attisdropped; + + IF v_logtab_cols = 0 THEN + RAISE EXCEPTION 'could not check relation: % (columns = %)', v_logtab_fqn, v_logtab_cols; + ELSIF v_pk_count != 1 THEN + RAISE EXCEPTION 'could not check relation: (missing pkey) % in table %', logtab_pk, v_logtab_fqn; + ELSE + RAISE NOTICE 'log table: OK (% columns)', v_logtab_cols; + END IF; + + -- Check restore table + IF EXISTS(SELECT 1 FROM pg_catalog.pg_class + WHERE relname=restoretab AND relkind='r') THEN + RAISE EXCEPTION 'restore table already exists: %', restoretab; + ELSE + RAISE NOTICE 'restore table: OK (doesnt exists)'; + END IF; + + -- create restore table + v_sql := 'CREATE'; + IF not_temporarly = 0 THEN + v_sql := v_sql || ' TEMPORARY'; + END IF; + v_sql := v_sql || format(' TABLE %I AS SELECT * FROM %s', restoretab, v_origtab_fqn); + IF search_pk IS NOT NULL THEN + v_sql := v_sql || format(' WHERE %I = %L', origtab_pk, search_pk); + END IF; + IF method = 0 THEN + RAISE NOTICE 'need logs from start to timestamp: %', to_timestamp; + v_sql := v_sql || ' LIMIT 0'; -- Create blank table to roll forward into (need all logs) + ELSE + RAISE NOTICE 'need logs from end to timestamp: %', to_timestamp; + END IF; + + -- RAISE NOTICE 'DDL: %', v_sql; + EXECUTE v_sql; + + -- now build query for getting logs + v_sql := format('SELECT * FROM %s WHERE ', v_logtab_fqn); + IF method = 0 THEN + v_sql := v_sql || format('trigger_changed <= %L', to_timestamp); -- ROLL FORWARD + ELSE + v_sql := v_sql || format('trigger_changed >= %L', to_timestamp); -- ROLL BACK + END IF; + + IF search_pk IS NOT NULL THEN + v_sql := v_sql || format(' AND %I = %L', origtab_pk, search_pk); + END IF; + + IF method = 0 THEN + v_sql := v_sql || format(' ORDER BY %I ASC', logtab_pk); + ELSE + v_sql := v_sql || format(' ORDER BY %I DESC', logtab_pk); + END IF; + + -- RAISE NOTICE 'SQL: %', v_sql; + + FOR v_rec IN EXECUTE v_sql + LOOP + IF v_rec.trigger_mode = 'UPDATE' AND ((method = 0 AND v_rec.trigger_tuple = 'old') OR (method = 1 AND v_rec.trigger_tuple = 'new')) THEN + -- For previous update row versions we needn't apply anything; + -- we just note the pk value for the quals when applying the + -- next row change, i.e when rolling forward the old pk value, + -- when rolling back the new pk value + EXECUTE format('SELECT ($1::text::%s).%I', v_logtab_fqn, origtab_pk) INTO v_old_pk_str USING v_rec; + ELSE + -- Apply the row changes from the log table, the following is + -- a mass of substitutions, but essentially we're selecting + -- data out of the log table record and casting it into the + -- restore table. + + IF v_rec.trigger_mode = 'UPDATE' THEN + v_sql := format('UPDATE %I SET (%s) = (SELECT %s FROM (SELECT ($1::text::%s).*) t) WHERE %I = %L', + restoretab, v_cols, v_cols, v_logtab_fqn, origtab_pk, v_old_pk_str); + ELSIF (v_rec.trigger_mode = 'INSERT' AND method = 0) OR (v_rec.trigger_mode = 'DELETE' AND method != 0) THEN + v_sql := format('INSERT INTO %I (%s) SELECT %s FROM (SELECT ($1::text::%s).*) t', + restoretab, v_cols, v_cols, v_logtab_fqn); + ELSIF (v_rec.trigger_mode = 'INSERT' AND method != 0) OR (v_rec.trigger_mode = 'DELETE' AND method = 0) THEN + v_sql := format('DELETE FROM %I WHERE %I = ($1::text::%s).%I', + restoretab, origtab_pk, v_logtab_fqn, origtab_pk); + ELSE + RAISE EXCEPTION 'unknown trigger_mode: %', trigger_mode; + END IF; + + -- RAISE NOTICE 'DML: %', v_sql; + EXECUTE v_sql USING v_rec; + END IF; + + END LOOP; + + RETURN quote_ident(restoretab); +END; +$BODY$ +LANGUAGE plpgsql VOLATILE; + +-- + +CREATE OR REPLACE FUNCTION table_log_pl_init(level int, orig_schema text, orig_name text, log_schema text, log_name text) +RETURNS void AS +$BODY$ +DECLARE + do_log_user int = 0; + level_create text = E''''; + orig_qq text; + log_qq text; +BEGIN + -- Quoted qualified names + orig_qq := quote_ident(orig_schema)||'.'||quote_ident(orig_name); + log_qq := quote_ident(log_schema)||'.'||quote_ident(log_name); + + IF level <> 3 THEN + level_create := level_create + ||', trigger_id BIGSERIAL NOT NULL PRIMARY KEY'; + IF level <> 4 THEN + level_create := level_create + ||', trigger_user VARCHAR(32) NOT NULL'; + do_log_user := 1; + IF level <> 5 THEN + RAISE EXCEPTION + 'table_log_pl_init: First arg has to be 3, 4 or 5.'; + END IF; + END IF; + END IF; + + EXECUTE 'CREATE TABLE '||log_qq + ||'(LIKE '||orig_qq + ||', trigger_mode VARCHAR(10) NOT NULL' + ||', trigger_tuple VARCHAR(5) NOT NULL' + ||', trigger_changed TIMESTAMPTZ NOT NULL' + ||level_create + ||')'; + + EXECUTE 'CREATE TRIGGER "table_log_trigger_pl" AFTER UPDATE OR INSERT OR DELETE ON ' + ||orig_qq||' FOR EACH ROW EXECUTE PROCEDURE table_log_pl(' + ||quote_literal(log_name)||',' + ||do_log_user||',' + ||quote_literal(log_schema)||')'; + + RETURN; +END; +$BODY$ +LANGUAGE plpgsql; + +CREATE OR REPLACE FUNCTION table_log_pl_init(level int, orig_name text) +RETURNS void AS + +$BODY$ +BEGIN + PERFORM table_log_pl_init(level, orig_name, current_schema()); + RETURN; +END; +$BODY$ +LANGUAGE plpgsql; + + +CREATE OR REPLACE FUNCTION table_log_pl_init(level int, orig_name text, log_schema text) +RETURNS void AS +$BODY$ +BEGIN + PERFORM table_log_pl_init(level, current_schema(), orig_name, log_schema); + RETURN; +END; +$BODY$ +LANGUAGE plpgsql; + + +CREATE OR REPLACE FUNCTION table_log_pl_init(level int, orig_schema text, orig_name text, log_schema text) +RETURNS void AS +$BODY$ +BEGIN + PERFORM table_log_pl_init(level, orig_schema, orig_name, log_schema, + CASE WHEN orig_schema=log_schema + THEN orig_name||'_log' ELSE orig_name END); + RETURN; +END; +$BODY$ +LANGUAGE plpgsql; diff --git a/sql/table_log_pl--unpackaged--0.1.sql b/sql/table_log_pl--unpackaged--0.1.sql new file mode 100644 index 0000000..e168d91 --- /dev/null +++ b/sql/table_log_pl--unpackaged--0.1.sql @@ -0,0 +1,8 @@ +\echo Use "CREATE EXTENSION table_log_pl FROM unpackaged" to load this file. \quit + +ALTER EXTENSION table_log_pl ADD FUNCTION table_log_pl(); +ALTER EXTENSION table_log_pl ADD FUNCTION table_log_pl_restore_table(varchar, varchar, char, char, char, timestamptz, char, int, int, varchar, varchar); +ALTER EXTENSION table_log_pl ADD FUNCTION table_log_pl_init(int, text, text, text, text); +ALTER EXTENSION table_log_pl ADD FUNCTION table_log_pl_init(int, text); +ALTER EXTENSION table_log_pl ADD FUNCTION table_log_pl_init(int, text, text); +ALTER EXTENSION table_log_pl ADD FUNCTION table_log_pl_init(int, text, text, text); diff --git a/sql/table_log_pl.sql b/sql/table_log_pl.sql new file mode 100644 index 0000000..804e2f2 --- /dev/null +++ b/sql/table_log_pl.sql @@ -0,0 +1,379 @@ +-- +-- Glyn Astill 28/08/2015 +-- +-- Attempt at pl/pgsql drop-in replacement for table_log C extenstion AKA +-- pg Table Audit / PostgreSQL Table Log / tablelog by Andreas Scherbaum +-- http://www.postgresql.org/ftp/projects/pgFoundry/tablelog/tablelog/ +-- http://github.com/andreasscherbaum/table_log +-- +-- A slightly more up to date version of the original C extension can +-- also be found here: +-- https://github.com/glynastill/pg_table_audit +-- +-- There are now many better ways to audit DML, using json types or +-- advanced extensions like pgaudit (below), however if for some reason +-- you're stuck with table_log this may help. +-- +-- http://8kb.co.uk/blog/2015/01/19/copying-pavel-stehules-simple-history-table-but-with-the-jsonb-type/ +-- https://github.com/2ndQuadrant/pgaudit + +SET search_path TO public; + +-- +DROP FUNCTION IF EXISTS table_log_pl (); -- ignore any error (but do not CASCADE) +DROP FUNCTION IF EXISTS table_log_pl_restore_table(varchar, varchar, char, char, char, timestamptz, char, int, int, varchar, varchar); + +-- + +CREATE OR REPLACE FUNCTION table_log_pl() RETURNS TRIGGER AS +$BODY$ +DECLARE + v_tabname text; + v_loguser boolean := false; + v_nspname text; + v_num_col int; + v_num_col_log int; + v_col_trig text := ''; + v_val_trig text := ''; + v_cols text := ''; + v_sql text; + v_col_cache text; + v_max_cache int; + v_enable_cache boolean := true; +BEGIN + -- Notes: + -- - The trigger_id comes off sequence, this function is oblivious + -- - 3 columns means don't log trigger_user or trigger_id + -- - 4 columns means don't log trigger_user + -- - 5 columns means log both + -- - To use the column data caching on server versions prior to + -- 9.6 add custom var "table_log.column_cache = ''" to postgresql.conf + + IF (TG_NARGS > 2) THEN + v_nspname := TG_ARGV[2]; + ELSE + v_nspname := TG_TABLE_SCHEMA; + END IF; + + IF (TG_NARGS > 1 AND TG_ARGV[1]::int = 1) THEN + v_loguser := true; + END IF; + + IF (TG_NARGS > 0) THEN + v_tabname := TG_ARGV[0]; + ELSE + v_tabname := TG_TABLE_NAME || '_log'; + END IF; + + -- Retrieve custom variable used as a poor mans cache for multirow statements + IF (v_enable_cache) THEN + IF (current_setting('server_version_num')::int >= 90600) THEN + v_col_cache := current_setting('table_log.column_cache', true); + ELSE + v_col_cache := current_setting('table_log.column_cache'); + END IF; + END IF; + + IF (v_enable_cache AND left(v_col_cache, length(TG_RELID::text)+1) = (TG_RELID::text || ':')) THEN + v_cols := right(v_col_cache, (length(TG_RELID::text)+1)*-1); + ELSE + IF (TG_WHEN != 'AFTER') THEN + RAISE EXCEPTION 'table_log: must be fired after event'; + END IF; + IF (TG_LEVEL = 'STATEMENT') THEN + RAISE EXCEPTION 'table_log: can''t process STATEMENT events'; + END IF; + + SELECT count(*), string_agg(quote_ident(attname),',') INTO STRICT v_num_col, v_cols + FROM pg_catalog.pg_attribute + WHERE attrelid = TG_RELID + AND attnum > 0 + AND NOT attisdropped; + + IF (v_num_col < 1) THEN + RAISE EXCEPTION 'table_log: number of columns in table is < 1, can this happen?'; + END IF; + + SELECT count(*) INTO STRICT v_num_col_log + FROM pg_catalog.pg_attribute + WHERE attrelid = (v_nspname || '.' || v_tabname)::regclass + AND attnum > 0 + AND NOT attisdropped; + + IF (v_num_col_log < 1) THEN + RAISE EXCEPTION 'could not get number columns in relation %.%', v_nspname, v_tabname; + END IF; + + -- This is the way the original checks column count regardless of trigger_id is presence + IF (v_num_col_log != (v_num_col + 3 + v_loguser::int)) AND (v_num_col_log != (v_num_col + 4 + v_loguser::int)) THEN + RAISE EXCEPTION 'number colums in relation %.%(%) does not match columns in %.%(%)', TG_TABLE_SCHEMA, TG_TABLE_NAME, v_num_col, v_nspname, v_tabname, v_num_col_log; + END IF; + + -- Set custom variable for use as a poor mans cache for multirow statements + IF (v_enable_cache) THEN + v_col_cache := (TG_RELID::text || ':' || v_cols); + PERFORM set_config('table_log.column_cache', v_col_cache, true); + END IF; + END IF; + + IF (v_loguser) THEN + v_col_trig := v_col_trig || ', "trigger_user"'; + v_val_trig := format('%L, ', session_user); + END IF; + v_col_trig := v_col_trig || ', "trigger_mode", "trigger_changed", "trigger_tuple"'; + v_val_trig := format('%s%L, %L', v_val_trig, TG_OP, current_timestamp); + + IF (TG_OP != 'INSERT') THEN + v_sql := format('INSERT INTO %I.%I (%s%s) SELECT %s, %s, ''old'' FROM (SELECT ($1::text::%I).*) t', v_nspname, v_tabname, v_cols, v_col_trig, v_cols, v_val_trig, TG_RELID::regclass); + EXECUTE v_sql USING OLD; + END IF; + IF (TG_OP != 'DELETE') THEN + v_sql := format('INSERT INTO %I.%I (%s%s) SELECT %s, %s, ''new'' FROM (SELECT ($1::text::%I).*) t', v_nspname, v_tabname, v_cols, v_col_trig, v_cols, v_val_trig, TG_RELID::regclass); + EXECUTE v_sql USING NEW; + RETURN NEW; + ELSE + RETURN OLD; + END IF; + +END; +$BODY$ +LANGUAGE plpgsql VOLATILE; + +-- + +CREATE OR REPLACE FUNCTION table_log_pl_restore_table (origtab varchar, origtab_pk varchar, logtab char, logtab_pk char, restoretab char, to_timestamp timestamptz, search_pk char DEFAULT NULL, method int DEFAULT 0, not_temporarly int DEFAULT 0, origtab_schema varchar DEFAULT NULL, logtab_schema varchar DEFAULT NULL) RETURNS varchar AS +$BODY$ +DECLARE + v_origtab_cols int; + v_logtab_cols int; + v_restoretab_cols int; + v_origtab_fqn text; + v_logtab_fqn text; + v_sql text; + v_cols text; + v_pk_count int; + v_rec record; + v_old_pk_str text; +BEGIN + + -- Notes: + -- + -- The original implimentation doesn't allow fully qualified table + -- references in table_log_restore_table; You can get some milage + -- out of search_path if required there. For this reason the plpgsql + -- version adds the following two optional parameters to those below: + -- + -- - original table schema + -- - logging table schema + -- + -- Comments from C implimentation: + -- + -- restore a complete table based on the logging table + -- + -- parameter: + -- - original table name + -- - name of primary key in original table + -- - logging table + -- - name of primary key in logging table + -- - restore table name + -- - timestamp for restoring data + -- - primary key to restore (only this key will be restored) (optional) + -- - restore mode + -- 0: restore from blank table (default) + -- needs a complete logging table + -- 1: restore from actual table backwards + -- - dont create table temporarly + -- 0: create restore table temporarly (default) + -- 1: create restore table not temporarly + -- return: + -- not yet defined + + IF origtab IS NULL THEN + RAISE NOTICE 'table_log_restore_table: missing original table name'; + END IF; + IF origtab_pk IS NULL THEN + RAISE NOTICE 'table_log_restore_table: missing primary key name for original table'; + END IF; + IF logtab IS NULL THEN + RAISE NOTICE 'table_log_restore_table: missing log table name'; + END IF; + IF logtab_pk IS NULL THEN + RAISE NOTICE 'table_log_restore_table: missing primary key name for log table'; + END IF; + IF restoretab IS NULL THEN + RAISE NOTICE 'table_log_restore_table: missing copy table name'; + END IF; + IF to_timestamp IS NULL THEN + RAISE NOTICE 'table_log_restore_table: missing timestamp'; + END IF; + IF (search_pk IS NOT NULL) THEN + RAISE NOTICE 'table_log_restore_table: will restore a single key'; + END IF; + + IF origtab_pk = logtab_pk THEN + RAISE EXCEPTION 'pkey of logging table cannot be the pkey of the original table: % <-> %', origtab_pk, logtab_pk; + END IF; + + v_origtab_fqn := coalesce(quote_ident(origtab_schema) || '.','') || quote_ident(origtab); + v_logtab_fqn := coalesce(quote_ident(logtab_schema) || '.','') || quote_ident(logtab); + + -- Check original table and get column list + SELECT string_agg(quote_ident(attname), ','), count(*), count(*) filter (where attname=origtab_pk) + INTO v_cols, v_origtab_cols, v_pk_count + FROM pg_catalog.pg_class c + JOIN pg_catalog.pg_attribute a ON a.attrelid = c.oid + JOIN pg_catalog.pg_namespace n ON c.relnamespace = n.oid + WHERE c.relname = origtab AND c.relkind='r' AND a.attnum > 0 + AND (origtab_schema IS NULL OR n.nspname = origtab_schema) + AND NOT attisdropped; + + IF v_origtab_cols = 0 OR v_cols IS NULL THEN + RAISE EXCEPTION 'could not check relation: % (columns = %)', v_origtab_fqn, v_origtab_cols; + ELSIF v_pk_count != 1 THEN + RAISE EXCEPTION 'could not check relation: (missing pkey) % in table %', origtab_pk, v_origtab_fqn; + ELSE + RAISE NOTICE 'original table: OK (% columns)', v_origtab_cols; + END IF; + + -- Check log table + SELECT count(*), count(*) filter (where attname=logtab_pk) + INTO v_logtab_cols, v_pk_count + FROM pg_catalog.pg_class c + JOIN pg_catalog.pg_attribute a ON a.attrelid = c.oid + JOIN pg_catalog.pg_namespace n ON c.relnamespace = n.oid + WHERE c.relname = logtab AND c.relkind='r' AND a.attnum > 0 + AND (logtab_schema IS NULL OR n.nspname = logtab_schema) + AND NOT attisdropped; + + IF v_logtab_cols = 0 THEN + RAISE EXCEPTION 'could not check relation: % (columns = %)', v_logtab_fqn, v_logtab_cols; + ELSIF v_pk_count != 1 THEN + RAISE EXCEPTION 'could not check relation: (missing pkey) % in table %', logtab_pk, v_logtab_fqn; + ELSE + RAISE NOTICE 'log table: OK (% columns)', v_logtab_cols; + END IF; + + -- Check restore table + IF EXISTS(SELECT 1 FROM pg_catalog.pg_class + WHERE relname=restoretab AND relkind='r') THEN + RAISE EXCEPTION 'restore table already exists: %', restoretab; + ELSE + RAISE NOTICE 'restore table: OK (doesnt exists)'; + END IF; + + -- create restore table + v_sql := 'CREATE'; + IF not_temporarly = 0 THEN + v_sql := v_sql || ' TEMPORARY'; + END IF; + v_sql := v_sql || format(' TABLE %I AS SELECT * FROM %s', restoretab, v_origtab_fqn); + IF search_pk IS NOT NULL THEN + v_sql := v_sql || format(' WHERE %I = %L', origtab_pk, search_pk); + END IF; + IF method = 0 THEN + RAISE NOTICE 'need logs from start to timestamp: %', to_timestamp; + v_sql := v_sql || ' LIMIT 0'; -- Create blank table to roll forward into (need all logs) + ELSE + RAISE NOTICE 'need logs from end to timestamp: %', to_timestamp; + END IF; + + -- RAISE NOTICE 'DDL: %', v_sql; + EXECUTE v_sql; + + -- now build query for getting logs + v_sql := format('SELECT * FROM %s WHERE ', v_logtab_fqn); + IF method = 0 THEN + v_sql := v_sql || format('trigger_changed <= %L', to_timestamp); -- ROLL FORWARD + ELSE + v_sql := v_sql || format('trigger_changed >= %L', to_timestamp); -- ROLL BACK + END IF; + + IF search_pk IS NOT NULL THEN + v_sql := v_sql || format(' AND %I = %L', origtab_pk, search_pk); + END IF; + + IF method = 0 THEN + v_sql := v_sql || format(' ORDER BY %I ASC', logtab_pk); + ELSE + v_sql := v_sql || format(' ORDER BY %I DESC', logtab_pk); + END IF; + + -- RAISE NOTICE 'SQL: %', v_sql; + + FOR v_rec IN EXECUTE v_sql + LOOP + IF v_rec.trigger_mode = 'UPDATE' AND ((method = 0 AND v_rec.trigger_tuple = 'old') OR (method = 1 AND v_rec.trigger_tuple = 'new')) THEN + -- For previous update row versions we needn't apply anything; + -- we just note the pk value for the quals when applying the + -- next row change, i.e when rolling forward the old pk value, + -- when rolling back the new pk value + EXECUTE format('SELECT ($1::text::%s).%I', v_logtab_fqn, origtab_pk) INTO v_old_pk_str USING v_rec; + ELSE + -- Apply the row changes from the log table, the following is + -- a mass of substitutions, but essentially we're selecting + -- data out of the log table record and casting it into the + -- restore table. + + IF v_rec.trigger_mode = 'UPDATE' THEN + v_sql := format('UPDATE %I SET (%s) = (SELECT %s FROM (SELECT ($1::text::%s).*) t) WHERE %I = %L', + restoretab, v_cols, v_cols, v_logtab_fqn, origtab_pk, v_old_pk_str); + ELSIF (v_rec.trigger_mode = 'INSERT' AND method = 0) OR (v_rec.trigger_mode = 'DELETE' AND method != 0) THEN + v_sql := format('INSERT INTO %I (%s) SELECT %s FROM (SELECT ($1::text::%s).*) t', + restoretab, v_cols, v_cols, v_logtab_fqn); + ELSIF (v_rec.trigger_mode = 'INSERT' AND method != 0) OR (v_rec.trigger_mode = 'DELETE' AND method = 0) THEN + v_sql := format('DELETE FROM %I WHERE %I = ($1::text::%s).%I', + restoretab, origtab_pk, v_logtab_fqn, origtab_pk); + ELSE + RAISE EXCEPTION 'unknown trigger_mode: %', trigger_mode; + END IF; + + -- RAISE NOTICE 'DML: %', v_sql; + EXECUTE v_sql USING v_rec; + END IF; + + END LOOP; + + RETURN quote_ident(restoretab); +END; +$BODY$ +LANGUAGE plpgsql VOLATILE; + +-- tests + +-- drop old trigger +DROP TRIGGER test_log_chg ON test; -- ignore any error + +-- create demo table +DROP TABLE test; -- ignore any error +CREATE TABLE test ( + id INT NOT NULL + PRIMARY KEY, + name VARCHAR(20) NOT NULL +); + +-- create the table without data from demo table +DROP TABLE test_log; -- ignore any error +SELECT * INTO test_log FROM test LIMIT 0; +ALTER TABLE test_log ADD COLUMN trigger_mode VARCHAR(10); +ALTER TABLE test_log ADD COLUMN trigger_tuple VARCHAR(5); +ALTER TABLE test_log ADD COLUMN trigger_changed TIMESTAMPTZ; +ALTER TABLE test_log ADD COLUMN trigger_id BIGINT; +CREATE SEQUENCE test_log_id; +SELECT SETVAL('test_log_id', 1, FALSE); +ALTER TABLE test_log ALTER COLUMN trigger_id SET DEFAULT NEXTVAL('test_log_id'); + +-- create trigger +CREATE TRIGGER test_log_chg AFTER UPDATE OR INSERT OR DELETE ON test FOR EACH ROW + EXECUTE PROCEDURE table_log_pl(); + +-- test trigger +INSERT INTO test VALUES (1, 'name'); +SELECT * FROM test; +SELECT * FROM test_log; +UPDATE test SET name='other name' WHERE id=1; +SELECT * FROM test; +SELECT * FROM test_log; + +-- create restore table +SELECT table_log_pl_restore_table('test', 'id', 'test_log', 'trigger_id', 'test_recover', NOW()); +SELECT * FROM test_recover; diff --git a/sql/table_log_pl_init.sql b/sql/table_log_pl_init.sql new file mode 100644 index 0000000..8cdfaba --- /dev/null +++ b/sql/table_log_pl_init.sql @@ -0,0 +1,83 @@ +SET search_path TO public; + +CREATE OR REPLACE FUNCTION table_log_pl_init(level int, orig_schema text, orig_name text, log_schema text, log_name text) +RETURNS void AS +$BODY$ +DECLARE + do_log_user int = 0; + level_create text = E''''; + orig_qq text; + log_qq text; +BEGIN + -- Quoted qualified names + orig_qq := quote_ident(orig_schema)||'.'||quote_ident(orig_name); + log_qq := quote_ident(log_schema)||'.'||quote_ident(log_name); + + IF level <> 3 THEN + level_create := level_create + ||', trigger_id BIGSERIAL NOT NULL PRIMARY KEY'; + IF level <> 4 THEN + level_create := level_create + ||', trigger_user VARCHAR(32) NOT NULL'; + do_log_user := 1; + IF level <> 5 THEN + RAISE EXCEPTION + 'table_log_pl_init: First arg has to be 3, 4 or 5.'; + END IF; + END IF; + END IF; + + EXECUTE 'CREATE TABLE '||log_qq + ||'(LIKE '||orig_qq + ||', trigger_mode VARCHAR(10) NOT NULL' + ||', trigger_tuple VARCHAR(5) NOT NULL' + ||', trigger_changed TIMESTAMPTZ NOT NULL' + ||level_create + ||')'; + + EXECUTE 'CREATE TRIGGER "table_log_trigger_pl" AFTER UPDATE OR INSERT OR DELETE ON ' + ||orig_qq||' FOR EACH ROW EXECUTE PROCEDURE table_log_pl(' + ||quote_literal(log_name)||',' + ||do_log_user||',' + ||quote_literal(log_schema)||')'; + + RETURN; +END; +$BODY$ +LANGUAGE plpgsql; + +CREATE OR REPLACE FUNCTION table_log_pl_init(level int, orig_name text) +RETURNS void AS + +$BODY$ +BEGIN + PERFORM table_log_pl_init(level, orig_name, current_schema()); + RETURN; +END; +$BODY$ +LANGUAGE plpgsql; + + +CREATE OR REPLACE FUNCTION table_log_pl_init(level int, orig_name text, log_schema text) +RETURNS void AS +$BODY$ +BEGIN + PERFORM table_log_pl_init(level, current_schema(), orig_name, log_schema); + RETURN; +END; +$BODY$ +LANGUAGE plpgsql; + + +CREATE OR REPLACE FUNCTION table_log_pl_init(level int, orig_schema text, orig_name text, log_schema text) +RETURNS void AS +$BODY$ +BEGIN + PERFORM table_log_pl_init(level, orig_schema, orig_name, log_schema, + CASE WHEN orig_schema=log_schema + THEN orig_name||'_log' ELSE orig_name END); + RETURN; +END; +$BODY$ +LANGUAGE plpgsql; + diff --git a/sql/uninstall_table_log_pl.sql b/sql/uninstall_table_log_pl.sql new file mode 100644 index 0000000..f515a4a --- /dev/null +++ b/sql/uninstall_table_log_pl.sql @@ -0,0 +1,12 @@ +BEGIN; + +-- drop old functions +DROP FUNCTION IF EXISTS table_log_pl (); -- ignore any error (but do not CASCADE) +DROP FUNCTION IF EXISTS table_log_pl_restore_table(varchar, varchar, char, char, char, timestamptz, char, int, int, varchar, varchar); + +DROP FUNCTION IF EXISTS table_log_pl_init(int, text, text, text, text); +DROP FUNCTION IF EXISTS table_log_pl_init(int, text); +DROP FUNCTION IF EXISTS table_log_pl_init(int, text, text); +DROP FUNCTION IF EXISTS table_log_pl_init(int, text, text, text); + +COMMIT; diff --git a/table_log_pl.control b/table_log_pl.control new file mode 100644 index 0000000..4f7d0bc --- /dev/null +++ b/table_log_pl.control @@ -0,0 +1,3 @@ +comment = 'pl/pgsql implementation for table_log: an extension to log table changes in PostgreSQL' +default_version = '0.1' +relocatable = true -- 2.39.2