I am new to Cassandra, I am trying to create a table and materialized view. but it not working.
My queries are:
-- all_orders
create table all_orders (
id uuid,
order_number bigint,
country text,
store_number bigint,
supplier_number bigint,
flow_type int,
planned_delivery_date timestamp,
locked boolean,
primary key ( order_number,store_number,supplier_number,planned_delivery_date ));
-- orders_by_date
CREATE MATERIALIZED VIEW orders_by_date AS
SELECT
id,
order_number,
country,
store_number,
supplier_number,
flow_type,
planned_delivery_date,
locked,
FROM all_orders
WHERE planned_delivery_date IS NOT NULL AND order_number IS NOT NULL
PRIMARY KEY ( planned_delivery_date )
WITH CLUSTERING ORDER BY (store_number,supplier_number);
I am getting an exception like this:
SyntaxException: <ErrorMessage code=2000 [Syntax error in CQL query]
message="line 1:7 no viable alternative at input 'MATERIALIZED' ([CREATE] MATERI
ALIZED...)">
Materialized Views in Cassandra solves the use case of not having to maintain additional table(s) for querying by different partition keys. But comes with following restrictions
Use all base table primary keys in the materialized view as primary keys.
Optionally, add one non-PRIMARY KEY column from the base table to the
materialized view's PRIMARY KEY.
Static columns are not supported as a PRIMARY KEY.
More documentation reference here.
So the correct syntax in your case of adding the materialized view would be
CREATE MATERIALIZED VIEW orders_by_date AS
SELECT id,
order_number,
country,
store_number,
supplier_number,
flow_type,
planned_delivery_date,
locked
FROM all_orders
WHERE planned_delivery_date IS NOT NULL AND order_number IS NOT NULL AND store_number IS NOT NULL AND supplier_number IS NOT NULL
PRIMARY KEY ( planned_delivery_date, store_number, supplier_number, order_number );
Here planned_delivery_date is the partition key and the rows are ordered by store_number, supplier_number, order_number (essentially the clustering columns). So there isn't a mandatory requirement to add "CLUSTERING ORDER BY" clause here.
Related
Hi I am new to Cassandra.
We are working on IOT project where car sensor data will be stored in cassandra.
Here is the example of one table where I am going to store one of the sensor data.
This is some sample data.
The way I want to partition the data is based on the organization_id so that different organization data is partitioned.
Here is the create table command:
CREATE TABLE IF NOT EXISTS engine_speed (
id UUID,
engine_speed_rpm text,
position int,
vin_number text,
last_updated timestamp,
organization_id int,
odometer int,
PRIMARY KEY ((id, organization_id), vin_number)
);
This works fine. However all my queries will be as bellow:
select * from engine_speed
where vin_number='xyz'
and organization_id = 1
and last_updated >='from time stamp' and last_updated <='to timestamp'
Almost all queries in all the table will have similar / same where clause.
I am getting error and it is asking to add "Allow filtering".
Kindly let me know how do I partition the table and define right primary key and indexs so that I don't have to add "allow filtering" in the query.
Apologies for this basic question but I'm just starting using cassandra.(using apache cassandra:3.11.12 )
The order of where clause should match with the order of partition and clustering keys you have defined in your DDL and you cannot skip any part of primary key while applying the WHERE clause before using the next key. So as per the query pattern u have defined, you can try the below DDL:
CREATE TABLE IF NOT EXISTS autonostix360.engine_speed (
vin_number text,
organization_id int,
last_updated timestamp,
id UUID,
engine_speed_rpm text,
position int,
odometer int,
PRIMARY KEY ((vin_number, organization_id), last_updated)
);
But remember,
PRIMARY KEY ((vin_number, organization_id), last_updated)
PRIMARY KEY ((vin_number), organization_id, last_updated)
above two are different in Cassandra, In case 1 your data will be partitioned by combination of vin_number and organization_id while last_updated will act as ordering key. In case 2, your data will be partitioned only by vin_number while organization_id and last_updated will act as ordering key. So you need to figure out which case suits your use case.
I am new to Cassandra, I am trying to create a materialized view. But it is not working.
Below is the table and materialized view definition along with the error code-
Table
CREATE TABLE my_keyspace.my_table (
customerno text,
operatorname text,
customername text,
operatorno text,
PRIMARY KEY (customerno));
Materialized view
CREATE MATERIALIZED VIEW op
AS SELECT operatorname,operatorno
FROM my_keyspace.my_table
WHERE operatorname IS NOT NULL AND customerno IS NOT NULL
PRIMARY KEY (operatorname, customerno);
ERROR Message while creating materialized view
invalidrequest: error from server: code=2200 [invalid query]
message="unknown column customerno referenced in primary key
for materialized view 'op'"
customerno is a primary key in the base table.
That error is indicating that customerno also needs to be in the SELECT clause from the base table. This should work:
> CREATE MATERIALIZED VIEW op AS SELECT operatorname, operatorno, customerno
FROM stackoverflow.customer_table
WHERE operatorname IS NOT NULL AND customerno IS NOT NULL
PRIMARY KEY (operatorname, customerno);
To add to Aaron's answer, it seems like you're running an older version of Cassandra.
In later versions of 3.0+ and 3.11, all primary key columns of the base table are automatically included so your CREATE statement should've worked.
For example if I run it on C* 3.0.10 (without customerno in the SELECT clause):
CREATE MATERIALIZED VIEW op
AS SELECT operatorname,operatorno
FROM my_keyspace.my_table
WHERE operatorname IS NOT NULL AND customerno IS NOT NULL
PRIMARY KEY (operatorname, customerno);
A DESCRIBE on the view returns:
cqlsh> DESCRIBE MATERIALIZED VIEW my_keyspace.op;
CREATE MATERIALIZED VIEW my_keyspace.op AS
SELECT operatorname, customerno, operatorno
FROM my_keyspace.my_table
WHERE operatorname IS NOT NULL AND customerno IS NOT NULL
PRIMARY KEY (operatorname, customerno)
WITH CLUSTERING ORDER BY (customerno ASC)
...
with customerno automatically included:
...
SELECT operatorname, customerno, operatorno
...
Cheers!
I'm using Cassandra 3.0.
My table was created with this query, but when I try to insert data into the table, I get the error: 'Some cluster keys are missing: created'
Table Structure:
CREATE TABLE db.feed (
action_object_id int,
owner_id int,
created timeuuid,
action_object text,
action_object_type int,
actor text,
feed_type text,
target text,
target_type int,
verb text,
PRIMARY KEY (action_object_id, owner_id, created)
) WITH CLUSTERING ORDER BY (owner_id ASC, created ASC)
You must have to provide values for all the primary keys. action_object_id, owner_id, created must have to be mentioned in your insert query.
Ex: insert into db.feed(action_object_id, owner_id, created, ...) values (?,?,?,...). And you cannot provide NULL values for primary keys. created cannot be null.
This is the query I used to create the table:
CREATE TABLE test.comments (msguuid timeuuid, page text, userid text, username text, msg text, timestamp int, PRIMARY KEY (timestamp, msguuid));
then I create a materialized view:
CREATE MATERIALIZED VIEW test.comments_by_page AS
SELECT *
FROM test.comments
WHERE page IS NOT NULL AND msguuid IS NOT NULL
PRIMARY KEY (page, timestamp, msguuid)
WITH CLUSTERING ORDER BY (msguuid DESC);
I want to get the last 50 rows sorted by timestamp in ascending order.
This is the query I'm trying:
SELECT * FROM test.comments_by_page WHERE page = 'test' AND timestamp < 1496707057 ORDER BY timestamp ASC LIMIT 50;
which then gives this error: InvalidRequest: code=2200 [Invalid query] message="Order by currently only support the ordering of columns following their declared order in the PRIMARY KEY"
How can I accomplish this?
Materialized View rules are basically the same of "standard" tables ones. If you want a specific order you must specify that in the clustering key.
So you have to put your timestamp into the clustering section.
clustering order statement should be modified as below:
//Don't forget to put the primary key before timestamp into ()
CLUSTERING ORDER BY ((msguuid DESC), timestamp ASC)
I created a one table posts. When I make request SELECT:
return $this->db->query('SELECT * FROM "posts" WHERE "id" IN(:id) LIMIT '.$this->limit_per_page, ['id' => $id]);
I get error:
PRIMARY KEY column "id" cannot be restricted (preceding column
"post_at" is either not restricted or by a non-EQ relation)
My table dump is:
CREATE TABLE posts (
id uuid,
post_at timestamp,
user_id bigint,
name text,
category set<text>,
link varchar,
image set<varchar>,
video set<varchar>,
content map<text, text>,
private boolean,
PRIMARY KEY (user_id,post_at,id)
)
WITH CLUSTERING ORDER BY (post_at DESC);
I read some article about PRIMARY AND CLUSTER KEYS, and understood, when there are some primary keys - I need use operator = with IN. In my case, i can not use a one PRIMARY KEY. What you advise me to change in table structure, that error will disappear?
My dummy table structure
CREATE TABLE posts (
id timeuuid,
post_at timestamp,
user_id bigint,
PRIMARY KEY (id,post_at,user_id)
)
WITH CLUSTERING ORDER BY (post_at DESC);
And after inserting some dummy data
I ran query select * from posts where id in (timeuuid1,timeuuid2,timeuuid3);
I was using cassandra 2.0 with cql 3.0