YOLO

README.md

-# CS631-Project
+# CS631-Project: Automatic Index creation in postgres.
 
+***Authors** @meet.doshi @gaurangathavale @jiteshg*
+
+---
+
+#### For checking patch updates 
+```
+Just look at the following files
+execMain.c
+nodeSeqScan.c
+worker_spi/worker_spi.c
+Makefile
+
+Look for following tags
+/* CS631 start */
+/* CS631 end */
+```
+
+###File Structure:
+
+```
+<22m0742_22m0752>
+├── execMain.c ~ User queries without where clause dont reach node sequential scan level. So they have to be stored at execMain level. Currently we are only saving insert and delete queries.
+├── nodeSeqScan.c ~ Operates at table level. Here we are keeping track of all select queries with and without where clause.
+├── worker_spi/ ~ This module should be registered in contrib folder and requires updates in the make file in same folder.
+│   ├── worker_spi.c ~ This is the daemon process which runs every 20 seconds. It alternates with a toggle where first time it fetches info and decides which index to create. On the next round it executes the query and creates the index.
+└── readme.md
+
+```
+
+
+###Tasks:
+
+1. Storing logs of incoming user queries for later use on making a decision whether to create an index or not.
+2. Creating a daemon process like a cron job for the database which runs regularly to check whether indexes need to be created or not.
+3. Building up logic for the daemon process to decided whether indexes need to be created or deleted.
+
+###Cautions:
+1. Installing worker module correctly and updating makefiles.
+2. Accessing uninitialized or modifying static memory.
+3. Recursive loops inside code.
+4. Codebase changes due to changes in postgres versions. So be sure to check if the data structures and libraries are matching. 
+5. Mutliple where clauses and subqueries.
+6. Current postgres version 13.7 `Different from the git version`
\ No newline at end of file

worker_spi/.gitignore

+# Generated subdirectories
+/log/
+/results/
+/tmp_check/

worker_spi/Makefile

+# src/test/modules/worker_spi/Makefile
+
+MODULES = worker_spi
+
+EXTENSION = worker_spi
+DATA = worker_spi--1.0.sql
+PGFILEDESC = "worker_spi - background worker example"
+
+REGRESS = worker_spi
+
+# enable our module in shared_preload_libraries for dynamic bgworkers
+REGRESS_OPTS = --temp-config $(top_srcdir)/contrib/worker_spi/dynamic.conf
+
+# Disable installcheck to ensure we cover dynamic bgworkers.
+NO_INSTALLCHECK = 1
+
+ifdef USE_PGXS
+PG_CONFIG = pg_config
+PGXS := $(shell $(PG_CONFIG) --pgxs)
+include $(PGXS)
+else
+subdir = contrib/worker_spi
+top_builddir = ../../
+include $(top_builddir)/src/Makefile.global
+include $(top_srcdir)/contrib/contrib-global.mk
+endif

worker_spi/dynamic.conf

+shared_preload_libraries = worker_spi
+worker_spi.database = contrib_regression

worker_spi/expected/worker_spi.out

+CREATE EXTENSION worker_spi;
+SELECT worker_spi_launch(4) IS NOT NULL;
+ ?column? 
+----------
+ t
+(1 row)
+
+-- wait until the worker completes its initialization
+DO $$
+DECLARE
+	visible bool;
+	loops int := 0;
+BEGIN
+	LOOP
+		visible := table_name IS NOT NULL
+			FROM information_schema.tables
+			WHERE table_schema = 'schema4' AND table_name = 'counted';
+		IF visible OR loops > 120 * 10 THEN EXIT; END IF;
+		PERFORM pg_sleep(0.1);
+		loops := loops + 1;
+	END LOOP;
+END
+$$;
+INSERT INTO schema4.counted VALUES ('total', 0), ('delta', 1);
+SELECT pg_reload_conf();
+ pg_reload_conf 
+----------------
+ t
+(1 row)
+
+-- wait until the worker has processed the tuple we just inserted
+DO $$
+DECLARE
+	count int;
+	loops int := 0;
+BEGIN
+	LOOP
+		count := count(*) FROM schema4.counted WHERE type = 'delta';
+		IF count = 0 OR loops > 120 * 10 THEN EXIT; END IF;
+		PERFORM pg_sleep(0.1);
+		loops := loops + 1;
+	END LOOP;
+END
+$$;
+SELECT * FROM schema4.counted;
+ type  | value 
+-------+-------
+ total |     1
+(1 row)
+

worker_spi/sql/worker_spi.sql

+CREATE EXTENSION worker_spi;
+SELECT worker_spi_launch(4) IS NOT NULL;
+-- wait until the worker completes its initialization
+DO $$
+DECLARE
+	visible bool;
+	loops int := 0;
+BEGIN
+	LOOP
+		visible := table_name IS NOT NULL
+			FROM information_schema.tables
+			WHERE table_schema = 'schema4' AND table_name = 'counted';
+		IF visible OR loops > 120 * 10 THEN EXIT; END IF;
+		PERFORM pg_sleep(0.1);
+		loops := loops + 1;
+	END LOOP;
+END
+$$;
+INSERT INTO schema4.counted VALUES ('total', 0), ('delta', 1);
+SELECT pg_reload_conf();
+-- wait until the worker has processed the tuple we just inserted
+DO $$
+DECLARE
+	count int;
+	loops int := 0;
+BEGIN
+	LOOP
+		count := count(*) FROM schema4.counted WHERE type = 'delta';
+		IF count = 0 OR loops > 120 * 10 THEN EXIT; END IF;
+		PERFORM pg_sleep(0.1);
+		loops := loops + 1;
+	END LOOP;
+END
+$$;
+SELECT * FROM schema4.counted;

worker_spi/worker_spi--1.0.sql

+/* src/test/modules/worker_spi/worker_spi--1.0.sql */
+
+-- complain if script is sourced in psql, rather than via CREATE EXTENSION
+\echo Use "CREATE EXTENSION worker_spi" to load this file. \quit
+
+CREATE FUNCTION worker_spi_launch(pg_catalog.int4)
+RETURNS pg_catalog.int4 STRICT
+AS 'MODULE_PATHNAME'
+LANGUAGE C;

worker_spi/worker_spi.control

+# worker_spi extension
+comment = 'Sample background worker'
+default_version = '1.0'
+module_pathname = '$libdir/worker_spi'
+relocatable = true