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BASIC POSTGRESQL
6-
PostgreSQL Brief History 30 minLecture1.1
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PostgreSQL Features 20 minLecture1.2
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PostgreSQL Monitoring Tools Overview 30 minLecture1.3
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PostgreSQL – Oracle Vs PostgreSQL 30 minLecture1.4
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PostgreSQL Data Types 30 minLecture1.5
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PostgreSQL Maximum Objects Size 30 minLecture1.6
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VMWARE & POSTGRESQL INSTALLATION
9-
Vmware Installation 30 minLecture2.1
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Creating Linux Virtual Machine 01 hourLecture2.2
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PostgreSQL Installation Types 30 minLecture2.3
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PostgreSQL GUI Installation 30 minLecture2.4
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PostgreSQL Text Mode Installation 30 minLecture2.5
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PostgreSQL Unattended Mode Installation 30 minLecture2.6
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Configure the network & Disk Partition 30 minLecture2.7
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How to install PostgreSQL10 On Linux Server ? 20 minLecture2.8
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PostgreSQL -11 Installation (rpm & source code) 30 minLecture2.9
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POSTGRESQL DATABASE
6-
Connect Postgres Server 10 minLecture3.1
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PostgreSQL startup / shutdown /restart the postgresql server 30 minLecture3.2
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PostgreSQL .bash_profile Set Up 30 minLecture3.3
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PostgreSQL Database Creation 30 minLecture3.4
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PostgreSQL Connect Database 30 minLecture3.5
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PostgreSQL Drop Database 30 minLecture3.6
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POSTGRESQL TABLE
16-
PostgreSQL Languages 30 minLecture4.1
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PostgreSQL Create Table 30 minLecture4.2
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PostgreSQL Select Table 30 minLecture4.3
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PostgreSQL Alter Table 30 minLecture4.4
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PostgreSQL Drop Table 30 minLecture4.5
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PostgreSQL Truncate Table 30 minLecture4.6
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PostgreSQL Rename 30 minLecture4.7
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PostgreSQL Comment 30 minLecture4.8
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PostgreSQL Insert 30 minLecture4.9
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PostgreSQL Update 30 minLecture4.10
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PostgreSQL Table Delete 30 minLecture4.11
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PostgreSQL Merge Table 30 minLecture4.12
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PostgreSQL UNION 30 minLecture4.13
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PostgreSQL UNION ALL 30 minLecture4.14
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PostgreSQL INTERSECT 30 minLecture4.15
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PostgreSQL DISTINCT 30 minLecture4.16
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USER/OBJECTS PRIVILEGE AND ROLES ASIGNING
3-
PostgreSQL Grant 30 minLecture5.1
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PostgreSQL Revoke 30 minLecture5.2
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Postgres user creation and restrict DDL statement & other database access 30 minLecture5.3
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TRANSACTIONS - MVCC
3-
PostgreSQL Commit 30 minLecture6.1
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PostgreSQL Rollback 30 minLecture6.2
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PostgreSQL Savepoint 30 minLecture6.3
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POSTGRESQL USER/SCHEMA MANAGEMENT
9-
PostgreSQL User Creation 30 minLecture7.1
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PostgreSQL User Creation Using Utility 30 minLecture7.2
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PostgreSQL Drop user 30 minLecture7.3
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PostgreSQL Drop User Using Utility 30 minLecture7.4
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PostgreSQL Password Changing and Views 30 minLecture7.5
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PostgreSQL Group/role 30 minLecture7.6
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Alter PostgreSQL User/Role/group 30 minLecture7.7
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PostgreSQL Schema 30 minLecture7.8
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PostgreSQL user creation and restrict DDL & database access 30 minLecture7.9
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POSTGRESQL CONSTRAINTS
6-
PostgreSQL Constraints 30 minLecture8.1
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PostgreSQL Primary Key 30 minLecture8.2
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PostgreSQL UNIQUE Constraint 30 minLecture8.3
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PostgreSQL CHECK Constraint 30 minLecture8.4
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PostgreSQL NOT NULL Constraint 30 minLecture8.5
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PostgreSQL Foreign Key 30 minLecture8.6
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POSTGRESQL ADVANCE DATA TYPE
5-
PostgreSQL DOMAIN Data Type 30 minLecture9.1
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PostgreSQL Alter Domain 30 minLecture9.2
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PostgreSQL Drop DOMAIN 30 minLecture9.3
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PostgreSQL Json Data Type 30 minLecture9.4
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PostgreSQL Sequence 30 minLecture9.5
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POSTGRESQL VIEWS
1-
How to Create PostgreSQL View 30 minLecture10.1
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POSTGRESQL MONITORING OBJECT USUAGE/SIZE
1 -
POSTGRESQL DATABASE ARCHITECTURE
4-
PostgreSQL Tablespace 30 minLecture12.1
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PostgreSQL UnderStanding Of Objects 30 minLecture12.2
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PostgreSQL Architecture 30 minLecture12.3
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PostgreSQL Query Flow 30 minLecture12.4
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POSTGRESQL BACKUP AND RECOVERY
13-
PostgreSQL Backup & Recovery Overview 30 minLecture13.1
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PostgreSQL Database Backup Tools – Pg_dump 30 minLecture13.2
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PostgreSQL Database Backup Tools – Pg_dumpall 30 minLecture13.3
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PostgreSQL Database Backup Tools – Pg_basebackup 30 minLecture13.4
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PostgreSQL COPY data From Text File 30 minLecture13.5
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PostgreSQL COPY data to Text File 30 minLecture13.6
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PostgreSQL Clone Table 20 minLecture13.7
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Postgres Database Schema Migration 30 minLecture13.8
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PostgreSQL Database clone/migration 30 minLecture13.9
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PostgreSQL Compress backup format 30 minLecture13.10
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PostgreSQL Archivelog 30 minLecture13.11
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PostgreSQL Point In Time Recovery 30 minLecture13.12
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Taking Backup On Postgres Slave (Standby) Server 30 minLecture13.13
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POSTGRESQL PERFORMANCE TUNING
5-
PostgreSQL Index 30 minLecture14.1
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PostgreSQL Reindex 30 minLecture14.2
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PostgreSQL PerformanceTuning 30 minLecture14.3
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Understanding Postgres VACUUM | VACUUM FULL | VACUUM ANALYZE 30 minLecture14.4
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Postgres Autovacuum Configuration/Setup 30 minLecture14.5
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HIGH AVAILABILITY, LOAD BALANCING, AND REPLICATION
11-
POSTGRESQL STREAMING REPLICATION 30 minLecture15.1
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SSL Streaming replication with PostgreSQL 10 30 minLecture15.2
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How to make Linux partition and configure the network on Redhat Linux7.3 30 minLecture15.3
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How To Fix Firewall Issues while connecting the other server? 30 minLecture15.4
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How to install the PostgreSQL10 On Linux ? 30 minLecture15.5
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How to Configure the cascade replication On PostgreSQL 10.3 ? 30 minLecture15.6
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How to add extra one slave an existing PostgreSQL cascade replication without down time ? 30 minLecture15.7
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PostgreSQL Switchover 30 minLecture15.8
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Postgres Failover 30 minLecture15.9
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Postgres Upgrade 30 minLecture15.10
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PostgreSQL Upgrade 9.5 to 11.3 . 30 minLecture15.11
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PostgreSQL CHECK Constraint
- CHECK constraint is the most generic constraint type. It allows you to specify that the value in a certain column must satisfy a Boolean (truth-value) expression.
- which allows the user to define a condition, that a value entered into a table, has to satisfy before it can be accepted. The CHECK constraint consists of the keyword CHECK followed by parenthesized conditions. The attempt will be rejected when update or insert column values that will make the condition false.
- Every time you insert a new row, PostgreSQL checks by using CHECK condition. If the condition is true the values will be inserted on particular table otherwise it would give back an error message and reject the changes. The same process is carried out for the update existing data.
PRACTICAL 1. CREATION OF CHECK CONSRAINTS:
CREATE TABLE products1 (
product_no integer CHECK(product_no > 0),
name text,
price numeric CHECK (price > 0)
);
postgres=# \d products1
Table "public.products1"
Column | Type | Modifiers
------------+---------+-----------
product_no | integer |
name | text |
price | numeric |
Check constraints:
"products1_price_check" CHECK (price > 0::numeric)
"products1_product_no_check" CHECK (product_no > 0)
PRACTICAL 2. CREATION OF CHECK CONSRAINTS WITH CONSTRAINT NAME:
CREATE TABLE products2 (
product_no integer,
name text,
price numeric CONSTRAINT positive_price CHECK (price > 0),
CONSTRAINT product_count CHECK (product_no > 0)
);
postgres=# \d products2
Table "public.products2"
Column | Type | Modifiers
------------+---------+-----------
product_no | integer |
name | text |
price | numeric |
Check constraints:
"positive_price" CHECK (price > 0::numeric)
"product_count" CHECK (product_no > 0)
There are two CHECK constraints in the products2 table:
First one is the PRICE of the products2 must be greater than 0. If you try to insert someone with PRICE below 0, you will receive an error message.This check will prevent from updating invalid Price in terms of their semantic meanings.
Second one also the product_no must be greater than 0,which is obvious.
PRACTICAL 3. INSERTING OPERATION ON CHECK CONSTRAINTS:
postgres=# insert into products2 values(1,'COFFEE',8),(2,'MILK',10),(3,'CHICKEN',12); INSERT 0 3 postgres=# insert into products2 values(1,'COFFEE',8),(2,'MILK',10),(3,'CHICKEN',12); INSERT 0 3 postgres=# insert into products2 values(0,'COFFEE',8),(2,'MILK',10),(3,'CHICKEN',12); ERROR: new row for relation "products2" violates check constraint "product_count" DETAIL: Failing row contains (0, COFFEE, 8). postgres=# insert into products2 values(1,'COFFEE',0),(2,'MILK',10),(3,'CHICKEN',12); ERROR: new row for relation "products2" violates check constraint "positive_price" DETAIL: Failing row contains (1, COFFEE, 0).
Becouse check constraint column product_no and price condition should be greater than 0 otherwise you will get error.
postgres=# select * from products2;
product_no | name | price
------------+---------+-------
1 | COFFEE | 8
2 | MILK | 10
3 | CHICKEN | 12
1 | COFFEE | 8
2 | MILK | 10
3 | CHICKEN | 12
(6 rows)
PRACTICAL 4.POSTGRESQL CHECK CONSTRAINTS FOR EXISTING TABLES:
postgres=# CREATE TABLE VILLAGE (
ID integer,
village_NAME VARCHAR (50),
area_code integer
);
postgres=# \dt village
List of relations
Schema | Name | Type | Owner
--------+---------+-------+----------
public | village | table | postgres
(1 row)
To add a (multicolumn) unique constraint to VILLAGE TABLE:
postgres=# ALTER TABLE VILLAGE ADD CONSTRAINT CHECK_NAME1 CHECK(ID>10); ALTER TABLE
Change the column area_code data type from integer to varchar becouse we need to set (char_length(AREA_CODE) = 5)
postgres=# alter table village alter column area_code type varchar;
ALTER TABLE
postgres=# ALTER TABLE VILLAGE ADD CONSTRAINT CHECK_NAME2 CHECK (char_length(AREA_CODE) = 5);
ALTER TABLE
postgres=# \d village
Table "public.village"
Column | Type | Modifiers
--------------+-----------------------+-----------
id | integer |
village_name | character varying(50) |
area_code | character varying |
Check constraints:
"check_name1" CHECK (id > 10)
"check_name2" CHECK (char_length(area_code::text) = 5)
Here id should be greater than 10 and area_code should be equal to 5 character otherwise you will receive error from following example i explained.
postgres=# insert into village values(11,'COFFEE','65483'); INSERT 0 1 postgres=# insert into village values(11,'COFFEE','6548'); ERROR: new row for relation "village" violates check constraint "check_name2" DETAIL: Failing row contains (11, COFFEE, 6548).
PRACTICAL 5. DROPPING CHECK CONSTRAINT USING ALTER TABLE STATEMENT:
postgres=# alter table VILLAGE drop constraint check_name1 ;
ALTER TABLE
postgres=# \d village
Table "public.village"
Column | Type | Modifiers
--------------+-----------------------+-----------
id | integer |
village_name | character varying(50) |
area_code | character varying |
Check constraints:
"check_name2" CHECK (char_length(area_code::text) = 5)
PRACTICAL 6. RENAME CONSTRAINT:
postgres=# ALTER TABLE VILLAGE RENAME CONSTRAINT check_name2 TO check_name3;
ALTER TABLE
postgres=# \d village
Table "public.village"
Column | Type | Modifiers
--------------+-----------------------+-----------
id | integer |
village_name | character varying(50) |
area_code | character varying |
Check constraints:
"check_name3" CHECK (char_length(area_code::text) = 5)
PRACTICAL 7. POSTGRESQL CONSTRAINT VIEWS:
if you want see all constraint name and table name(relname) you need to join pg_stat_all_tables and pg_constraint views
postgres=# select a.conname,a.contype,a.conrelid,b.relname,b.relid from pg_constraint a,pg_stat_all_tables b where a.conrelid=b.relid;
conname | contype | conrelid | relname | relid
----------------------------+---------+----------+----------------+-------
prikey | p | 24676 | films | 24676
production | u | 24697 | k | 24697
distributorc_did_check | c | 24702 | distributorc | 24702
uni_key | u | 24761 | india | 24761
code_title | p | 24710 | primtab | 24710
students_student_id_key | u | 24753 | students | 24753
pkey | p | 24735 | postgres3 | 24735
uni_constraint2 | u | 24784 | mobiles | 24784
mobiles_pkey | p | 24784 | mobiles | 24784
uni_constraint | u | 24773 | cellphones | 24773
cellphones_pkey | p | 24773 | cellphones | 24773
con1 | c | 24706 | distributorsct | 24706
postgres1_order_no_key | u | 24725 | postgres1 | 24725
mul_uni_key | u | 24766 | batch | 24766
distributors_pkey | p | 24690 | distributors | 24690
distributors_name_check | c | 24690 | distributors | 24690
products1_price_check | c | 24798 | products1 | 24798
products1_product_no_check | c | 24798 | products1 | 24798
product_count | c | 24806 | products2 | 24806
positive_price | c | 24806 | products2 | 24806
check_name2 | c | 24814 | village | 24814
postgres_ord_no_key | u | 24715 | postgres | 24715
(22 rows)