Re: CQL performance inserting multiple cluster keys under same partition key
On Tue, Aug 26, 2014 at 6:50 PM, Jaydeep Chovatia chovatia.jayd...@gmail.com wrote: Hi, I have question on inserting multiple cluster keys under same partition key. Ex: CREATE TABLE Employee ( deptId int, empId int, name varchar, address varchar, salary int, PRIMARY KEY(deptId, empId) ); BEGIN *UNLOGGED *BATCH INSERT INTO Employee (deptId, empId, name, address, salary) VALUES (1, 10, 'testNameA', 'testAddressA', 2); INSERT INTO Employee (deptId, empId, name, address, salary) VALUES (1, 20, 'testNameB', 'testAddressB', 3); APPLY BATCH; Here we are inserting two cluster keys (10 and 20) under same partition key (1). Q1) Is this batch transaction atomic and isolated? If yes then is there any performance overhead with this syntax? As long as the update are under the same partition key (and I insist, only in that condition), logged (the one without the UNLOGGED keyword) and unlogged batches behave *exactly* the same way. So yes, in that case the batch is atomic and isolated (though on the isolation, you may want to be aware that while technically isolated, the usual timestamp rules still apply and so you might not get the behavior you think if 2 batches have the same timestamp: see CASSANDRA-6123 https://issues.apache.org/jira/browse/CASSANDRA-6123). There is no also no performance overhead (assuming you meant over logged batches). Q2) Is this CQL syntax can be considered equivalent of Thrift batch_mutate? It is equivalent, both (the CQL syntax and Thrift batch_mutate) resolve to the same operation internally. -- Sylvain
Re: CQL performance inserting multiple cluster keys under same partition key
This clarifies my doubt. Thanks You Sylvain for your help. On Tue, Aug 26, 2014 at 11:59 PM, Sylvain Lebresne sylv...@datastax.com wrote: On Tue, Aug 26, 2014 at 6:50 PM, Jaydeep Chovatia chovatia.jayd...@gmail.com wrote: Hi, I have question on inserting multiple cluster keys under same partition key. Ex: CREATE TABLE Employee ( deptId int, empId int, name varchar, address varchar, salary int, PRIMARY KEY(deptId, empId) ); BEGIN *UNLOGGED *BATCH INSERT INTO Employee (deptId, empId, name, address, salary) VALUES (1, 10, 'testNameA', 'testAddressA', 2); INSERT INTO Employee (deptId, empId, name, address, salary) VALUES (1, 20, 'testNameB', 'testAddressB', 3); APPLY BATCH; Here we are inserting two cluster keys (10 and 20) under same partition key (1). Q1) Is this batch transaction atomic and isolated? If yes then is there any performance overhead with this syntax? As long as the update are under the same partition key (and I insist, only in that condition), logged (the one without the UNLOGGED keyword) and unlogged batches behave *exactly* the same way. So yes, in that case the batch is atomic and isolated (though on the isolation, you may want to be aware that while technically isolated, the usual timestamp rules still apply and so you might not get the behavior you think if 2 batches have the same timestamp: see CASSANDRA-6123 https://issues.apache.org/jira/browse/CASSANDRA-6123). There is no also no performance overhead (assuming you meant over logged batches). Q2) Is this CQL syntax can be considered equivalent of Thrift batch_mutate? It is equivalent, both (the CQL syntax and Thrift batch_mutate) resolve to the same operation internally. -- Sylvain
CQL performance inserting multiple cluster keys under same partition key
Hi, I have question on inserting multiple cluster keys under same partition key. Ex: CREATE TABLE Employee ( deptId int, empId int, name varchar, address varchar, salary int, PRIMARY KEY(deptId, empId) ); BEGIN *UNLOGGED *BATCH INSERT INTO Employee (deptId, empId, name, address, salary) VALUES (1, 10, 'testNameA', 'testAddressA', 2); INSERT INTO Employee (deptId, empId, name, address, salary) VALUES (1, 20, 'testNameB', 'testAddressB', 3); APPLY BATCH; Here we are inserting two cluster keys (10 and 20) under same partition key (1). Q1) Is this batch transaction atomic and isolated? If yes then is there any performance overhead with this syntax? Q2) Is this CQL syntax can be considered equivalent of Thrift batch_mutate? -jaydeep
Re: CQL performance inserting multiple cluster keys under same partition key
AFAIK, it is not. With CAS it should br On 26/08/2014 10:21 pm, Jaydeep Chovatia chovatia.jayd...@gmail.com wrote: Hi, I have question on inserting multiple cluster keys under same partition key. Ex: CREATE TABLE Employee ( deptId int, empId int, name varchar, address varchar, salary int, PRIMARY KEY(deptId, empId) ); BEGIN *UNLOGGED *BATCH INSERT INTO Employee (deptId, empId, name, address, salary) VALUES (1, 10, 'testNameA', 'testAddressA', 2); INSERT INTO Employee (deptId, empId, name, address, salary) VALUES (1, 20, 'testNameB', 'testAddressB', 3); APPLY BATCH; Here we are inserting two cluster keys (10 and 20) under same partition key (1). Q1) Is this batch transaction atomic and isolated? If yes then is there any performance overhead with this syntax? Q2) Is this CQL syntax can be considered equivalent of Thrift batch_mutate? -jaydeep
Re: CQL performance inserting multiple cluster keys under same partition key
But if we look at thrift world batch_mutate then it used to perform all mutations withing partition key atomically without using CAS i.e no extra penalty. Does this mean CQL degrades in performance as compared to thrift if we want to do multiple updates to a partition key atomically? On Tue, Aug 26, 2014 at 11:51 AM, Vivek Mishra mishra.v...@gmail.com wrote: AFAIK, it is not. With CAS it should br On 26/08/2014 10:21 pm, Jaydeep Chovatia chovatia.jayd...@gmail.com wrote: Hi, I have question on inserting multiple cluster keys under same partition key. Ex: CREATE TABLE Employee ( deptId int, empId int, name varchar, address varchar, salary int, PRIMARY KEY(deptId, empId) ); BEGIN *UNLOGGED *BATCH INSERT INTO Employee (deptId, empId, name, address, salary) VALUES (1, 10, 'testNameA', 'testAddressA', 2); INSERT INTO Employee (deptId, empId, name, address, salary) VALUES (1, 20, 'testNameB', 'testAddressB', 3); APPLY BATCH; Here we are inserting two cluster keys (10 and 20) under same partition key (1). Q1) Is this batch transaction atomic and isolated? If yes then is there any performance overhead with this syntax? Q2) Is this CQL syntax can be considered equivalent of Thrift batch_mutate? -jaydeep
