This is one of the important post for all PostgreSQL Database Administrator who are dealing with Bulk Insertion in their PostgreSQL Server.

We should optimize Bulk Insertion operation because It is also utilizing more system resources.

Few steps to increase the performance of Bulk Insertion:

• If It is only one time data load, remove all Index and create after INSERT. For regular Bulk Insertion, look into Index part and try to optimize it.
• Take a backup of all the Triggers and drop all the Triggers.
• Use COPY command instead of INSERT.
• If you can not use COPY command because of of INSERT multiple value, you should not give more than 1000 multiple values in single INSERT. All INSERT multiple values stored in the memory area which may decrease the INSERT performance.
• Disable other database logging process.
• If BULK INSERTION is running with a single transaction, you should also disable all FOREIGN KEYs and later you can enable it.
• Change synchronous_commit=off to reduce the cost of committing.
• Change Checkpoint default configuration, Increase the checkpoint_segments value.
• Increase the size of shared_buffers, effective_cache_size, work_mem.
• Prepared all statements on server side.
• Disable Auto-Vacuum on Table.
• Disable Auto Database Backup process.
• Increase the system resource (Memory, Disk, CPU), If it is required.
• Use SSD type of Disk for faster storage.

Note: Whatever you changed for BULK INSERTION, please do not forget to rollback after completion of BULK INSERTION.

I found that PostgreSQL professionals are wondering about last inserted id or sequence value of PostgreSQL Tables.

You can find an N number of articles and discussion on this point.

Let me clear describe this topic in my words, because this is important for PostgreSQL Database Developers.

The PostgreSQL provideds Sequence object and you can create a Sequence by assigning SERIAL or BIGSERIAL Datatype to the columns.

You can use CURRVAL and LASTVAL to get the last inserted or generated ID by the Sequence object.

These both are concurrently safe, and behaviour of Postgres Sequence is designed such a way that different sessions will not interfere with each other.

But sometimes, I found the wrong ID by CURRVAL or LASTVAL because there is some additional trigger rule written like when you insert one row in X table, some other row also require to insert in Y table using an INSERT Trigger.

When some extra insertion or load of insertion is going on by the different sources, LASTVAL and CURRVAL return the wrong ID. This is the very rare situation, but still, the risk is there.

The best solution is – PostgreSQL INSERT RETURNING:
Using INSERT RETURNING, you can select last inserted id for that only INSERT at the time of insertion.

Below is a small demo:

Create a sample table:

CREATE TABLE tbl_TestReturnID 
(
	Rno SERIAL 
	,Name CHARACTER VARYING
	,Address CHARACTER VARYING
	,CONSTRAINT pk_tbl_TestReturnID_Rno PRIMARY KEY(Rno)
);

Insertion with RETURNING a last inserted value:

INSERT INTO tbl_TestReturnID (Name,Address) 
VALUES ('Anvesh','Hyderabad') RETURNING Rno;

After executing above INSERT statement, you will get the last inserted ID.
My Suggestion is to use RETURNING instead of CURRVAL and LASTVAL.

Many times we require to insert all countries into a database system. In this post, I am sharing the Country data with required insert statements.

We can store this data into Country table. The application has to just select list of Countries from this country table.

Below is a sample Country table and insert script for all Countries:

CREATE TABLE tbl_Countries
(
     CountryID INT
    ,CountryName VARCHAR(50)
    ,TwoCharCountryCode CHAR(2)
    ,ThreeCharCountryCode CHAR(3)    
);


INSERT INTO tbl_Countries VALUES 
(1,'Afghanistan','AF','AFG')
,(2,'Aland Islands','AX','ALA')
,(3,'Albania','AL','ALB')
,(4,'Algeria','DZ','DZA')
,(5,'American Samoa','AS','ASM')
,(6,'Andorra','AD','AND')
,(7,'Angola','AO','AGO')
,(8,'Anguilla','AI','AIA')
,(9,'Antarctica','AQ','ATA')
,(10,'Antigua and Barbuda','AG','ATG')
,(11,'Argentina','AR','ARG')
,(12,'Armenia','AM','ARM')
,(13,'Aruba','AW','ABW')
,(14,'Australia','AU','AUS')
,(15,'Austria','AT','AUT')
,(16,'Azerbaijan','AZ','AZE')
,(17,'Bahamas','BS','BHS')
,(18,'Bahrain','BH','BHR')
,(19,'Bangladesh','BD','BGD')
,(20,'Barbados','BB','BRB')
,(21,'Belarus','BY','BLR')
,(22,'Belgium','BE','BEL')
,(23,'Belize','BZ','BLZ')
,(24,'Benin','BJ','BEN')
,(25,'Bermuda','BM','BMU')
,(26,'Bhutan','BT','BTN')
,(27,'Bolivia','BO','BOL')
,(28,'Bonaire, Sint Eustatius and Saba','BQ','BES')
,(29,'Bosnia and Herzegovina','BA','BIH')
,(30,'Botswana','BW','BWA')
,(31,'Bouvet Island','BV','BVT')
,(32,'Brazil','BR','BRA')
,(33,'British Indian Ocean Territory','IO','IOT')
,(34,'Brunei','BN','BRN')
,(35,'Bulgaria','BG','BGR')
,(36,'Burkina Faso','BF','BFA')
,(37,'Burundi','BI','BDI')
,(38,'Cambodia','KH','KHM')
,(39,'Cameroon','CM','CMR')
,(40,'Canada','CA','CAN')
,(41,'Cape Verde','CV','CPV')
,(42,'Cayman Islands','KY','CYM')
,(43,'Central African Republic','CF','CAF')
,(44,'Chad','TD','TCD')
,(45,'Chile','CL','CHL')
,(46,'China','CN','CHN')
,(47,'Christmas Island','CX','CXR')
,(48,'Cocos (Keeling) Islands','CC','CCK')
,(49,'Colombia','CO','COL')
,(50,'Comoros','KM','COM')
,(51,'Congo','CG','COG')
,(52,'Cook Islands','CK','COK')
,(53,'Costa Rica','CR','CRI')
,(54,'Ivory Coast','CI','CIV')
,(55,'Croatia','HR','HRV')
,(56,'Cuba','CU','CUB')
,(57,'Curacao','CW','CUW')
,(58,'Cyprus','CY','CYP')
,(59,'Czech Republic','CZ','CZE')
,(60,'Democratic Republic of the Congo','CD','COD')
,(61,'Denmark','DK','DNK')
,(62,'Djibouti','DJ','DJI')
,(63,'Dominica','DM','DMA')
,(64,'Dominican Republic','DO','DOM')
,(65,'Ecuador','EC','ECU')
,(66,'Egypt','EG','EGY')
,(67,'El Salvador','SV','SLV')
,(68,'Equatorial Guinea','GQ','GNQ')
,(69,'Eritrea','ER','ERI')
,(70,'Estonia','EE','EST')
,(71,'Ethiopia','ET','ETH')
,(72,'Falkland Islands (Malvinas)','FK','FLK')
,(73,'Faroe Islands','FO','FRO')
,(74,'Fiji','FJ','FJI')
,(75,'Finland','FI','FIN')
,(76,'France','FR','FRA')
,(77,'French Guiana','GF','GUF')
,(78,'French Polynesia','PF','PYF')
,(79,'French Southern Territories','TF','ATF')
,(80,'Gabon','GA','GAB')
,(81,'Gambia','GM','GMB')
,(82,'Georgia','GE','GEO')
,(83,'Germany','DE','DEU')
,(84,'Ghana','GH','GHA')
,(85,'Gibraltar','GI','GIB')
,(86,'Greece','GR','GRC')
,(87,'Greenland','GL','GRL')
,(88,'Grenada','GD','GRD')
,(89,'Guadaloupe','GP','GLP')
,(90,'Guam','GU','GUM')
,(91,'Guatemala','GT','GTM')
,(92,'Guernsey','GG','GGY')
,(93,'Guinea','GN','GIN')
,(94,'Guinea-Bissau','GW','GNB')
,(95,'Guyana','GY','GUY')
,(96,'Haiti','HT','HTI')
,(97,'Heard Island and McDonald Islands','HM','HMD')
,(98,'Honduras','HN','HND')
,(99,'Hong Kong','HK','HKG')
,(100,'Hungary','HU','HUN')
,(101,'Iceland','IS','ISL')
,(102,'India','IN','IND')
,(103,'Indonesia','ID','IDN')
,(104,'Iran','IR','IRN')
,(105,'Iraq','IQ','IRQ')
,(106,'Ireland','IE','IRL')
,(107,'Isle of Man','IM','IMN')
,(108,'Israel','IL','ISR')
,(109,'Italy','IT','ITA')
,(110,'Jamaica','JM','JAM')
,(111,'Japan','JP','JPN')
,(112,'Jersey','JE','JEY')
,(113,'Jordan','JO','JOR')
,(114,'Kazakhstan','KZ','KAZ')
,(115,'Kenya','KE','KEN')
,(116,'Kiribati','KI','KIR')
,(117,'Kosovo','XK','---')
,(118,'Kuwait','KW','KWT')
,(119,'Kyrgyzstan','KG','KGZ')
,(120,'Laos','LA','LAO')
,(121,'Latvia','LV','LVA')
,(122,'Lebanon','LB','LBN')
,(123,'Lesotho','LS','LSO')
,(124,'Liberia','LR','LBR')
,(125,'Libya','LY','LBY')
,(126,'Liechtenstein','LI','LIE')
,(127,'Lithuania','LT','LTU')
,(128,'Luxembourg','LU','LUX')
,(129,'Macao','MO','MAC')
,(130,'Macedonia','MK','MKD')
,(131,'Madagascar','MG','MDG')
,(132,'Malawi','MW','MWI')
,(133,'Malaysia','MY','MYS')
,(134,'Maldives','MV','MDV')
,(135,'Mali','ML','MLI')
,(136,'Malta','MT','MLT')
,(137,'Marshall Islands','MH','MHL')
,(138,'Martinique','MQ','MTQ')
,(139,'Mauritania','MR','MRT')
,(140,'Mauritius','MU','MUS')
,(141,'Mayotte','YT','MYT')
,(142,'Mexico','MX','MEX')
,(143,'Micronesia','FM','FSM')
,(144,'Moldava','MD','MDA')
,(145,'Monaco','MC','MCO')
,(146,'Mongolia','MN','MNG')
,(147,'Montenegro','ME','MNE')
,(148,'Montserrat','MS','MSR')
,(149,'Morocco','MA','MAR')
,(150,'Mozambique','MZ','MOZ')
,(151,'Myanmar (Burma)','MM','MMR')
,(152,'Namibia','NA','NAM')
,(153,'Nauru','NR','NRU')
,(154,'Nepal','NP','NPL')
,(155,'Netherlands','NL','NLD')
,(156,'New Caledonia','NC','NCL')
,(157,'New Zealand','NZ','NZL')
,(158,'Nicaragua','NI','NIC')
,(159,'Niger','NE','NER')
,(160,'Nigeria','NG','NGA')
,(161,'Niue','NU','NIU')
,(162,'Norfolk Island','NF','NFK')
,(163,'North Korea','KP','PRK')
,(164,'Northern Mariana Islands','MP','MNP')
,(165,'Norway','NO','NOR')
,(166,'Oman','OM','OMN')
,(167,'Pakistan','PK','PAK')
,(168,'Palau','PW','PLW')
,(169,'Palestine','PS','PSE')
,(170,'Panama','PA','PAN')
,(171,'Papua New Guinea','PG','PNG')
,(172,'Paraguay','PY','PRY')
,(173,'Peru','PE','PER')
,(174,'Phillipines','PH','PHL')
,(175,'Pitcairn','PN','PCN')
,(176,'Poland','PL','POL')
,(177,'Portugal','PT','PRT')
,(178,'Puerto Rico','PR','PRI')
,(179,'Qatar','QA','QAT')
,(180,'Reunion','RE','REU')
,(181,'Romania','RO','ROU')
,(182,'Russia','RU','RUS')
,(183,'Rwanda','RW','RWA')
,(184,'Saint Barthelemy','BL','BLM')
,(185,'Saint Helena','SH','SHN')
,(186,'Saint Kitts and Nevis','KN','KNA')
,(187,'Saint Lucia','LC','LCA')
,(188,'Saint Martin','MF','MAF')
,(189,'Saint Pierre and Miquelon','PM','SPM')
,(190,'Saint Vincent and the Grenadines','VC','VCT')
,(191,'Samoa','WS','WSM')
,(192,'San Marino','SM','SMR')
,(193,'Sao Tome and Principe','ST','STP')
,(194,'Saudi Arabia','SA','SAU')
,(195,'Senegal','SN','SEN')
,(196,'Serbia','RS','SRB')
,(197,'Seychelles','SC','SYC')
,(198,'Sierra Leone','SL','SLE')
,(199,'Singapore','SG','SGP')
,(200,'Sint Maarten','SX','SXM')
,(201,'Slovakia','SK','SVK')
,(202,'Slovenia','SI','SVN')
,(203,'Solomon Islands','SB','SLB')
,(204,'Somalia','SO','SOM')
,(205,'South Africa','ZA','ZAF')
,(206,'South Georgia and the South Sandwich Islands','GS','SGS')
,(207,'South Korea','KR','KOR')
,(208,'South Sudan','SS','SSD')
,(209,'Spain','ES','ESP')
,(210,'Sri Lanka','LK','LKA')
,(211,'Sudan','SD','SDN')
,(212,'Suriname','SR','SUR')
,(213,'Svalbard and Jan Mayen','SJ','SJM')
,(214,'Swaziland','SZ','SWZ')
,(215,'Sweden','SE','SWE')
,(216,'Switzerland','CH','CHE')
,(217,'Syria','SY','SYR')
,(218,'Taiwan','TW','TWN')
,(219,'Tajikistan','TJ','TJK')
,(220,'Tanzania','TZ','TZA')
,(221,'Thailand','TH','THA')
,(222,'Timor-Leste (East Timor)','TL','TLS')
,(223,'Togo','TG','TGO')
,(224,'Tokelau','TK','TKL')
,(225,'Tonga','TO','TON')
,(226,'Trinidad and Tobago','TT','TTO')
,(227,'Tunisia','TN','TUN')
,(228,'Turkey','TR','TUR')
,(229,'Turkmenistan','TM','TKM')
,(230,'Turks and Caicos Islands','TC','TCA')
,(231,'Tuvalu','TV','TUV')
,(232,'Uganda','UG','UGA')
,(233,'Ukraine','UA','UKR')
,(234,'United Arab Emirates','AE','ARE')
,(235,'United Kingdom','GB','GBR')
,(236,'United States','US','USA')
,(237,'United States Minor Outlying Islands','UM','UMI')
,(238,'Uruguay','UY','URY')
,(239,'Uzbekistan','UZ','UZB')
,(240,'Vanuatu','VU','VUT')
,(241,'Vatican City','VA','VAT')
,(242,'Venezuela','VE','VEN')
,(243,'Vietnam','VN','VNM')
,(244,'Virgin Islands, British','VG','VGB')
,(245,'Virgin Islands, US','VI','VIR')
,(246,'Wallis and Futuna','WF','WLF')
,(247,'Western Sahara','EH','ESH')
,(248,'Yemen','YE','YEM')
,(249,'Zambia','ZM','ZMB')
,(250,'Zimbabwe','ZW','ZWE');