Prasad,
> 1) What happens if the index is present filter column and sort column?
If there is an index on a needed column, then Ignite doesn't have to sort
data again. It just can use the index.
> If ignite pulls all data in heap then what the use of page size property
Page size specifies the
1) What happens if the index is present filter column and sort column?
If ignite pulls all data in heap then what the use of page size property.
Even if I set it to 500 ignite is going to pull all 3 million records in
heap space.
2) Does it not use disk space/file system like in external merge
Prasad,
Your understanding is correct. All entries will be pulled to heap and
sorted there.
In general, *SELECT * FROM table ORDER BY column *query processes all data
on heap, except for the cases, when there is an index on needed columns.
Denis
вт, 31 июл. 2018 г. в 8:44, Prasad Bhalerao :
>
1) Does ignite use heap space to do the required processing as per the
execution plan to retrieve the data from cache which is in off heap memory?
2) Please check the following SQL. This CACHE_1 has around 50 million
entries.
select * from (
select * from CACHE_1 where filter1 = ? (Q1)
UNION
