GUID vs INTDEBATE

Francisco J. CarabezV1.0 Feb 25 2014

INTADVANTAGE

Has better performance when used in joins, indexes and conditions.

Numeric values are easier to understand for application’s users if they are displayed.

Widely used for incrementing key values serially.

Less space for storing.

GUIDADVANTAGE

Unique across the [universe] servers.

Client side generated. With GUID, the client application can generate a new value and can send it to the server. It does not need to wait till the SAVE function returns to know what is the ID.

Consolidation and syncronization. You have Customer Table in 5 different Databases and you want to make a Data warehouse – no problem – the records can keep their keys.

GUIDANATOMY

A GUID is most commonly showed as text as a sequence of hexadecimal digits separated into five groups, such as:

{3F2504E0-4F89-41D3-9A0C-0305E82C3301}This text notation contains the following fields, separated by hyphens:

Hex digits Description8 Data14 Data24 Data34 Initial two bytes from Data412 Remaining six bytes from Data4

INT, BIGINT & GUIDSPACE

INTINT (4 bytes or 32bits)

++Native and faster to manage in older Pcs.

++Less space for Indexing.

BIGINT

GUID

BIGINT (8 bytes or 64bits)++Native and faster to manage in new Pcs.

+Moderate space for Indexing.

GUID (16 bytes or 128bits)+Practical without performance hits on new Pcs.

-Fragmentation hits on Indexing.

-More space for storing.

Cast BIGINT as GUID8THE BETTER OF BOTH WORLD

Practical unique for most database systems, meaning easier integration with replication

Semi-random client side or server side generated.

Semi-Sequential based on date-time stamp.

Not Fragmentation hits on indexes.

GUID8ANATOMY

LOW INT (lower 4 bytes)Hold seconds elapsed since Jan 1, 2000.

HIHI INT (upper 4 bytes)

Random number.

LOW

GUID8Date-time stamp RANGE?

One Year has 31536000 Seconds (365*24*60*60)

Lower INT can hold 4294967295

4294967295 / 31536000 = 136 years

The GUID8 time stamp approach is safe from YEAR 2000-2136

GUID8Probability of one DUPLICATE?

Lower INT hold the Date-Time stamp in seconds.

For every second, the upper INT can hold a

RANDOM Number in range from 0 to 4,294,967,295

So having a duplicate is possible but far probable.

FACTSON DATABASE MANAGEMENT

GUID is hard to read or typing... Yes but come on! if you're querying that much at once, you're probably doing it wrong anyhow.

No all tables needs a GUID.

Cost of storage are cheaper and computers are fasters.

GUID Allows asynchronous architectures more easily.

GUID guiltless used by: IPv6, Electronics Devices, Item tagging, OS…

GUID8GENERATION CODE SQL

SELECT

CAST(

(

CAST(

( EXTRACT(DAY FROM now()-'2001-01-01')*(24*60*60) ) +

( EXTRACT(HOUR FROM now()) * (60*60) ) +

( EXTRACT(MINUTE FROM now()) * (60) ) +

EXTRACT(SECOND FROM now())

AS BIGINT ) << 32

)

+

CAST ( CAST( ROUND(RANDOM()*999999999) AS INT) AS BIGINT )

AS BIGINT )

GUID8GENERATION CODE postgreSQL

DECLARE

IntLower int;

IntUpper int;

DateNow timestamp;

IntDias int;

IntHoras int;

IntMinutos int;

IntSegundos int;

BigIntReturn bigint;

BEGIN

DateNow = NOW();

IntDias = EXTRACT(DAY FROM DateNow-'2000-01-01'::date)::int;

IntHoras = EXTRACT(HOUR FROM DateNow)::int;

IntMinutos = EXTRACT(MINUTE FROM DateNow)::int;

IntSegundos = EXTRACT(SECOND FROM DateNow)::int;

IntLower := ( IntDias*(24*60*60) ) + IntHoras*(60*60) + IntMinutos*60 + IntSegundos;

IntUpper := ROUND(RANDOM()*999999999)::int;

BigIntReturn := (IntLower::bigint << 32)+IntUpper;

RETURN (BigIntReturn);

END;

OUR PROJECTREPLICATION & SINCRONATION

QUESTIONS?THANK YOU!

Download this presentation:http://www.carabez.com/downloads/sql_guid_vs_int.zip

More Info:http://es.wikipedia.org/wiki/Globally_unique_identifier

http://betterexplained.com/articles/the-quick-guide-to-guids/http://krow.livejournal.com/497839.html

http://blog.sqlauthority.com/2010/04/28/sql-server-guid-vs-int-your-opinion/

LINKSFor review: