If there is no space for new inserts in the database, and after that if I delete some rows, can I insert new rows immediately? or do I have to do shrink or use alter table move clause to reuse deleted blocks.
Oracle 10g

the rows you deleted free enough space then yes

so deleted blocks can be used for new inserts even if they are below high water mark
Am i right?

you need to give /*+append */ hint to put data over hwm.

so after deletion the deleted blocks below the hwm can be used for new inserts,I dont need to use alter table move or shrink clause right?

course not

shrink reset empty blocks whereas alter table move doesnt.Is it true?
What is the diffrence between shrink and alter table move

>> If there is no space for new inserts in the database, and after that if I delete some rows, can I insert new rows immediately?

It depends on your PCTUSED setting. Ifthe deletes moved the block onto the freelist, then "yes":

http://www.dba-oracle.com/oracle_tips_PCTFREE_PCTUSED.htm

>> What is the diffrence between shrink and alter table move

Good question!

http://www.dba-oracle.com/t_alter_table_mo...hrink_space.htm

Alter table move - The alter table xxx move command moves rows down into un-used space and adjusts the HWM but does not adjust the segments extents, and the table size remains the same. The alter table move syntax also preserves the index and constraint definitions.

Alter table shrink space - Using the "alter table xxx shrink space compact" command will re-pack the rows, move down the HWM, and releases unused extents.