Is it better to use NUMBER or VARCHAR2 performance wise?
Hi,
maybe it's a silly question,
but if i want to save a numeric code in my table is it better to use NUMBER or VARCHAR2, the code will never be use in any calculation.
I'm asking this because i have an idea that is to use NUMBER for a column type only when that value will be used in mathmatic calculations of some sort, if it's not going to be used in calculation i use VARCHAR2.
But other than my choice I've been wondering what is the best choice considering performance.
Can you help?
Best regards
Sentinel wrote:
Unless you need to preserve leading zeros, the number data type is the most appropriate data type to use for numeric data.I have to disagree I'm afraid.
"Leading zeros" is a display issue and should not determine how you store your data on the database. If you need to display leading zeros, then that should be done at the front-end. You can't determine future requirements against the data (businesses change their minds) so you will give yourself problems of updating your data if you find the business decides that another area should display it with e.g. another 2 leading zeros or they don't want leading zeros etc. Never store numbers as varchar for display purposes.
It's quite simple, if you are dealing with numbers, store them as numbers, if you are dealing with varchars store them as varchars, if you are dealing with dates and times, store them as date etc.
As for performance, there is no noticable difference between the datatypes... it's all Binary data when you get down to machine code level.
If you store numbers as varchar you could end up with other issues, apart from possible problems in calculations...
Comparisons against numbers stored as varchar are notoriously problematic...
SQL> select 'TRUE' from dual where '150' > '1000';
'TRU
TRUE
SQL> select 'TRUE' from dual where '150' < '1000';
no rows selected
SQL>... and then the developer wonders why the data isn't being returned. ;)
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