Re: Ordering of numbers generated by a sequence

[Ankit Singhal]

JFYI, phoenix.query.rowKeyOrderSaltedTable is deprecated and is
not honored from v4.4, so please use phoenix.query.force.rowkeyorder
instead.
I have updated the docs(http://localhost:8000/tuning.html) now accordingly.

On Mon, Oct 17, 2016 at 3:14 AM, Josh Elser  wrote:

> Not 100% sure, but yes, I believe this is correct. One of the servers
> would get 0-99, the other 100-199. The server to use up that batch of 100
> values would then request 200-299, etc. Setting the cache to be 0 would
> likely impact the performance of Phoenix.
>
> Using some external system to perform the global ordering may result in
> better performance. Some testing would probably be needed :)
>
> For the final rowKeyOrderSaltedTable question, yes, I believe that query
> would work as you intend.
>
>
> F21 wrote:
>
>> I am using Phoenix 4.8.1 with HBase 1.2.3 and the Phoenix Query Server.
>>
>> I want to use a sequence to generate a monotonically increasing id for
>> each row. Since the documentation states that 100 sequence numbers are
>> cached by default in the client (in my case, I assume the caching would
>> happen in the query server), what is the behavior if I have 2 query
>> servers (load-balanced)? Does this mean Server A would generate numbers
>> starting from 0, and Server B would generate numbers starting from 100?
>> I need to make sure that the id is in order on a global basis for the
>> whole table. Would setting the CACHE to 0 be the best of achieving this?
>>
>> Also, as the ID is monotonically increasing, I plan to salt the table
>> using something like (no manual split points):
>>
>> CREATE TABLE mytable (id BIGINT NOT NULL PRIMARY KEY,  VARCHAR)
>> SALT_BUCKETS = 20;
>>
>> Without setting phoenix.query.rowKeyOrderSaltedTable to true, would I
>> still be able to get my records in order if I select them using
>> something like this?
>>
>> SELECT * FROM mytable WHERE id > 5 && id < 100 ORDER BY id
>>
>> Thanks,
>>
>> Francis
>>
>>

Re: Ordering of numbers generated by a sequence

[Josh Elser]

Not 100% sure, but yes, I believe this is correct. One of the servers 
would get 0-99, the other 100-199. The server to use up that batch of 
100 values would then request 200-299, etc. Setting the cache to be 0 
would likely impact the performance of Phoenix.


Using some external system to perform the global ordering may result in 
better performance. Some testing would probably be needed :)


For the final rowKeyOrderSaltedTable question, yes, I believe that query 
would work as you intend.


F21 wrote:

I am using Phoenix 4.8.1 with HBase 1.2.3 and the Phoenix Query Server.

I want to use a sequence to generate a monotonically increasing id for
each row. Since the documentation states that 100 sequence numbers are
cached by default in the client (in my case, I assume the caching would
happen in the query server), what is the behavior if I have 2 query
servers (load-balanced)? Does this mean Server A would generate numbers
starting from 0, and Server B would generate numbers starting from 100?
I need to make sure that the id is in order on a global basis for the
whole table. Would setting the CACHE to 0 be the best of achieving this?

Also, as the ID is monotonically increasing, I plan to salt the table
using something like (no manual split points):

CREATE TABLE mytable (id BIGINT NOT NULL PRIMARY KEY,  VARCHAR)
SALT_BUCKETS = 20;

Without setting phoenix.query.rowKeyOrderSaltedTable to true, would I
still be able to get my records in order if I select them using
something like this?

SELECT * FROM mytable WHERE id > 5 && id < 100 ORDER BY id

Thanks,

Francis