Hi,
I have gone through this link
<https://apacheignite-sql.readme.io/docs/schema-and-indexes#section-group-indexes>,
but still have some doubts.
Please check the following example.
public class TestData
@QuerySqlField
private long id;
@QuerySqlField(orderedGroups = {@QuerySqlField.Group(name = "data_idx1",
*order* = 1)})
private long field1;
@QuerySqlField(orderedGroups = {@QuerySqlField.Group(name = "data_idx1",
*order* = 4)})
private int field2;
@QuerySqlField(orderedGroups = {@QuerySqlField.Group(name = "data_idx1",
*order* = 2)})
private int field3;
1) In this code I have created a group index on field1, field2 and field3.
field1 has order=1.
Does it mean that the rows will be sorted on first on *field1*(order=1) and
then *field3*(order=2) and then *field2*(order=4) ?
I am just trying to understand the significance of "ORDER".
2) Keeping the indexes as above, Will ignite be able to use the indexes in
following cases :
Please explain why if the ignite is not able to use the indexes.
I am trying to understand how ignite decides if it can use a index or not?
a) select * from TestData where field1 = ?
b) select * from TestData where field1 = ? and field2 = ?
c) select * from TestData where field2 = ?
d) select * from TestData where field3 = ?
e) select * from TestData where field2 = ? and field3 = ?
3) Should the columns in where clause be in order in which the group
indexes are defined to make use of indexes?
Prasad
