topic Re: Queries in Application Development and Automation Discussions

Queries

Former Member — Tue, 24 Oct 2006 09:30:36 GMT

Hi Experts,

1.How many primary keyfields can we create in a custom table?

2.What is the dis.adv. of using Secondary index?

Regards

Re: Queries

Former Member — Tue, 24 Oct 2006 09:32:47 GMT

All the table columns can be defined as key fields (not recommended)

Creating more indices is creating unnecessary overhead. Secondary index is never recommeneded except for some special cases.

Regards,

Sandeep Josyula

*Reward for helpful answers

Re: Queries

Former Member — Tue, 24 Oct 2006 09:39:34 GMT

There must be only 1 primary index, its maximum lenght you can find in the documentation. Indexes help to improve performance of sql queries, but keep in mind that the number of seconadary indexes should be limited because they are stored in database and they slow down saving data in database. There are also other performance reasons to limit their number.

Re: Queries

Former Member — Tue, 24 Oct 2006 10:55:48 GMT

Hi,

can any one pls explain what is the purpose of indix in the table, and what is primary index and secondary index ?

Thanks

Re: Queries

Former Member — Tue, 24 Oct 2006 13:14:15 GMT

Index is basically helpful while we do Database records retrival, search etc.

Primary Index is automatically created by the system for all the Key fields. Primary Index is always 0.

If we don't want to make a field, Primary field and still want to specify Index, we can create secondary index for that field. Secondary index starts with any number, alphabet, except 0.

Hope this helps.

Regards

- Atul