I have cache object structure in the below format,
key,List
How can the CacheJdbcPojoStoreFactory be used in keyfields of Ignite configuration. Can you provide an example?
The CacheJdbcPojoStoreFactory is largely designed to mirror the structure of your database table in Ignite. You don't mention which database you're using, but it's unlikely that it has a list datatype.
If you want to use the CacheJdbcPojoStoreFactory you'll need to normalise your cache structure in Ignite.
Alternatively, you can write your own cache store that will perform the mapping.
Related
Can I get some advice on whether it is possible to proceed like the steps below?
SQL Server data is loaded in Ignite Cluster
The data in SQL Server has been changed.
-> Is there any other way to reflect this changed data without reloading the data from SQL Server?
When used as a cache in front of the database, when changes are made directly to the DB without going through the Ignite Cluster, can the already loaded cache data be directly reflected in the Ignite cache?
Is it possible to set only the value to change without loading the data again?
If possible, which part should I set? Please.
I suppose the real question is - how to propagate changes applied to SQL Server first to the Apache Ignite cluster. And the short answer is - you need to do it by yourself, i.e. you need to implement some synchronization logic between the two databases. This should not be a complex task if most of the data updates come through Ignite and SQL Server-first updates are rare.
As for the general approach, you can check for the Change Data Capture (CDC) pattern implementations. There are multiple articles on how you can achieve it using external tools, for sample, CDC Between MySQL and GridGain With Debezium or this video.
It's worth mentioning that Apache Ignite is currently working on its own native implementation of CDC.
Take a look at Ignite's external storage integration, and the read/write through features. See: https://ignite.apache.org/docs/latest/persistence/external-storage
and https://ignite.apache.org/docs/latest/persistence/custom-cache-store
examples here: https://github.com/apache/ignite/tree/master/examples/src/main/java/org/apache/ignite/examples/datagrid/store
I'm working on a system which will fetch data from a service and put pieces of the response in to a cache and/or into a SQL table.
The cache is needed for consumption by other Java services directly. These services require a more direct connection than the SQL abstraction, so we need to connect directly to the cache.
The table is needed for a JDBC SQL connection to external SQL clients e.g. SQL Workbench, DBeaver, Tableau, 3rd party systems.
My question is how Ignite works regarding caches vs tables. I know it stores its caches as maps similar to other IMDGs. What I guess I don't understand is how that gets turned into a table, or what APIs are available to set/get between the two.
So the question is, how can I take an INSERT from the JDBC/SQL side and query it via the Cache? How can I add() into the Cache and SELECT it from the JDBC/SQL side? If I have a table named "foo", does that also create a cache named "foo"?
Or am I supposed to use one or the other and not bleed between the two? I haven't found many good examples of this, so it seems to be either you use caches or you use tables.
It would be extremely advantageous to have a bridge between the two. We're migrating to Ignite from an H2 implementation where we mushed a Hazelcast cache and H2's SQL together and are hoping Ignite, being built atop H2, has done something similar already.
In particular, I was hoping to use DataStreamers but I'm not finding much in the way of how it relates to the SQL/table side of things.
Ignite cache falls under key-value type of nosql database. You can fire SQL like query from java code to ignite caches as it supports it. For example,
SELECT _KEY, _VAL from "foo".val
Here, foo is your cache name and val is the value part of key-value pair. As this is all NOSQL, relating it to RDBMS SQL is not so much rational, still we can relate all non primary columns in SQL table to the fields of your value object and primary one to the key part.
So, in datastreamer, you can construct collection of key, value objects and stream it. This internally calls nothing but put operation on cache.
To select in SQL fashon, you can fire query like below-
SqlFieldsQuery query = new SqlFieldsQuery(queryString);
FieldsQueryCursor<List<?>> cursor = cache.query(query);
There are multiple ways to do this, SqlFieldsQuery is one of that.
This was answered couple times already, basically you need to refer to Query Entities, Indexed Types or key_type/value_type parameters of CREATE TABLE to make it work. I.e. every entry in cache of correct type will be a row of table and vice versa.
I am new to Apache Ignite. Can you please suggest a way to get a large data set (preferably CSVs along with DDL statements that is Ignite compliant), which I could use it to create schema, tables in Ignite (uses native persistence), to test a few use cases that I have.
You can use Web Console to copy data from relational DB into Apache Ignite, creating data structure and project files along the way.
Apply it on existing database or something like MySQL Employees sample database.
Web Console will connect to existing internally deployed Database using 'agent' program ran locally.
I am new at database administrator, i just want to mapping actually, how many kind of database are there. I made this map, i want to ask, Is it true ?
Simply, I wanna to make map likes Historical Tree / Genealogy of database.
https://drive.google.com/file/d/0B4VwAhmXH2OVbm8yTm9ld1oxY1E/view?usp=sharing
cassandra and hbase are column store databases. I think these are missing in NoSql databases and ArangoDB is a multi-model database which supports Key-value, document storage and graph
I am studying Redis, and I surprise how Redis works. I found that Redis, store recent data in cache in NoSQL format and have their own query for that. But I am curious about the following working:
How data store in persistence database. Do we need to fire same insert query in both the database?
If Redis uses NoSQL database is it compulsory that persistence database we are using is follow NoSQL structure?
How data synchronisation works between Redis database and persistence database?
Redis offers persistence. There are several options depending on what exactly do you need. Here is the official documentation.