I am new to superset and wanted to know if there's any way to perform data streaming in big query using apache superset? Currently, I have set up the database in apache superset with big query but when I update the table data using SQL commands in bigquery it doesn't reflect in superset. Is there any way to get the streaming of data to superset?
I've looked around the Apache Superset documentation and couldn't find anything related to "streaming data" from a source, what I think in this scenario is happening, is that you have a dashboard which use the data from the table you have in BigQuery, and after adding some new information to the table you expect that change to be reflected in the dashboard automatically.
Based on this my theory is that Superset saves the result of your query on memory or it could be using BigQuery cached results which may not allow the dashboard to automatically update the data and see the changes made. My suggestion is to either run again the query for your table to try to get the latest data. On the other hand, if Superset use cached results, you'll have to take a look at the configuration used for Superset for BigQuery looking for a way to disable it.
Related
I need to understand the below:
1.) How does one BigQuery connect to another BigQuery and apply some logic and create another BigQuery. For e.g if i have a ETL tool like Data Stage and we have some data been uploaded for us to consume in form of a BigQuery. So in DataStage or using any other technology how do i design the job so that the source is one BQ and the Target is another BQ.
2.) I want to achieve like my input will be a VIEW (BigQuery) and then need to run some logic on the BigQuery View and then load into another BigQuery view.
3.) What is the technology used to connected one BigQuery to another BigQuery is it https or any other technology.
Thanks
If you have a large amount of data to process (many GB), you should do the transformation of the data directly in the Big Query database. It would be very slow to extract all the data, run it through something locally, and send it back. You don't need any outside technology to make one view depend on another view, besides access to the relevant data.
The ideal job design will be an SQL query that Big Query can process. If you are trying to link tables/views across different projects then the source BQ table must be listed in fully-specified form projectName.datasetName.tableName in the FROM clauses of the SQL query. Project names are globally unique in Google Cloud.
Permissions to access the data must be set up correctly. BQ provides fine-grained control over who can access, and it is in the BQ documentation. You can also enable public access to all BQ users if that is appropriate.
Once you have that SQL query, you can create a new view by sending your SQL to Google BigQuery either through the command line (the bq tool), the web console, or an API.
1) You can use BigQuery Connector in DataStage to read and write to bigquery.
2) Bigquery use namespaces in the format project.dataset.table to access tables across projects. This allows you to manipulate your data in GCP as it were in the same database.
To manipulate your data you can use DML or standard SQL.
To execute your queries you can use the GCP Web console or client libraries such as python or java.
3) BigQuery is a RESTful web service and use HTTPS
I am trying to see if I can set up a trigger system, so whenever a new row of data is populated in these tables A, B, and C --> it populates new rows into a new table I created (table D, for example)?
I'm using Bigquery. Does this platform allow this capability?
Not sure what kind of coding should be used for this...(Insert into, etc.)
Maybe late to the party, but this is possible now. https://cloud.google.com/blog/topics/developers-practitioners/how-trigger-cloud-run-actions-bigquery-events
Triggers are not supported on BigQuery, basically because they are not aligned to the intended use patterns of the product. You may also refer to this existing question.
There is a Feature Request in place for an interesting approach to trigger an action when rows are loaded to BigQuery, but currently there is no ETA for it.
You my want to consider Cloud Composer as different alternative, instead of using triggers, you may orchestrate your data ingestion tasks.
BigQuery is a data warehouse, and there is no trigger support.
Have a look at https://cloud.google.com/sql/ , maybe it will help you.
I am designing a solution in which Google Cloud SQL will be used to store all data from the regular functioning of the app(kind of OLTP data). The data is expected to grow over time into pretty large size. The data itself is relational in nature and hence we have chosen Cloud SQL instead of Cloud Datastore.
This data needs to be fed into Big Query for analytics and this needs to be near real-time analytics (as the best case), although realistically some lag can be expected. But I am trying to design a solution which reduces this lag to minimum possible.
My question has 3 parts -
Should I use Cloud SQL for storing data and then move it to BigQuery or change the basic design itself and use BigQuery for storing the data initially as well? Is BigQuery suitable for use for regular, low-latency OLTP workloads?(I don't think so - is my assumption correct?)
What is the recommended/best practice for loading Cloud SQL data into BigQuery and have this integration work near real-time?
Is Cloud Dataflow a good option? If I connect Cloud SQL to Cloud DataFlow and further to BigQuery - will it work? Or is there any other way to achieve this which is better(as asked in question 2)?
Take a look at how WePay does this:
https://wecode.wepay.com/posts/bigquery-wepay
The MySQL to GCS operator executes a SELECT query against a MySQL
table. The SELECT pulls all data greater than (or equal to) the last
high watermark. The high watermark is either the primary key of the
table (if the table is append-only), or a modification timestamp
column (if the table receives updates). Again, the SELECT statement
also goes back a bit in time (or rows) to catch potentially dropped
rows from the last query (due to the issues mentioned above).
With Airflow they manage to keep BigQuery synchronized to their MySQL database every 15 minutes.
BigQuery supports Cloud SQL federated queries which lets you directly query Cloud SQL database from BigQuery. To keep Cloud SQL table in sync with BigQuery, you can write a simple script with following query to sync two tables every hour.
INSERT
demo.customers (column1)
SELECT
*
FROM
EXTERNAL_QUERY(
"project.us.connection",
"SELECT column1 FROM mysql_table WHERE timestamp > ${timestamp};");
Just remember replace the ${timestamp} with the current timestamp - 1 hour.
Another method would be to split the write process to CloudSQL and to Cloud Pub/Sub and then have a Dataflow reader to stream into BigQuery. This works well when you have materially different target schema for your BigQuery tables - which is common when denormalizing your relational data.
The upside is that you can reduce overall latency to say a few seconds; however, the main downside is that if your transactional data is highly mutating you will have to create a versioning scheme to track changes.
Google has provided a reference article on this subject related to using a change data capture tool to identify the changed data and only pushing that.
This makes some assumptions that may not work for you:
willingness to learn debezium
willingness to let GCP connect to your source MySQL database
If those work for your situation it seems like a good solution.
I think you can use federated queries as one possible solution:
A federated query is a way to send a query statement to an external database and get the result back as a temporary table. Federated queries use the BigQuery Connection API to establish a connection with the external database. In your standard SQL query, you use the EXTERNAL_QUERY function to send a query statement to the external database, using that database's SQL dialect. The results are converted to BigQuery standard SQL data types.
You can use federated queries with the following external databases:
Cloud Spanner
Cloud SQL
After the initial one-time setup, you can write a query with the EXTERNAL_QUERY SQL function.
I leave you the documentation so you can implement it on your project:
https://cloud.google.com/bigquery/docs/federated-queries-intro
I want to design Web UI which fetches data from HDFS. I want to generate some reports using this data which is stored in HDFS. I have my own custom reports format. I am writing REST API's to fetch data. But running HIVE queries gives latency issues Hence I want different approach for this, I could think of two.
Using IMPALA to create tables. But I am not sure about REST support for IMPALA.
Using HIVE but instead of MR use SPARK as execution engine. .
spark-job-server provides REST support, and fetch data with SPARK-SQL.
Which of the approach will be suitable or is there any better approach for this?
Please can anyone help as I am very new in this.
I'd prefer to choose impala if latency is the main consideration. It's dedicated to SQL processing on hdfs and does it well. About REST api and the application logic you are achieving, this seems to be a good example
We are very pleased with the combination BigQuery <-> Tableau Server with live connection. However, we now want to work with a data extract (500MB) on Tableau Server (since this datasource is not too big and is used very frequently). This takes too much time to refresh (1.5h+). We noticed that only 0.1% is query time and the rest is data export. Since the Tableau Server is on the same platform and location, latency should not be a problem.
This is similar to the slow export of a BigQuery table to a single file, which can be solved by using "daisy chain" option (wildcards). Unfortunately we can't use similar logic with a Google BigQuery data extract refresh in Tableau...
We have identified some approaches, but are not pleased with our current ideas:
Working with incremental refresh: our existing BigQuery table rows can change: these changes can only be applied in Tableau if you do a full refresh
Exporting the BigQuery table to GCS using the daisy chain option and making a Tableau data extract using the Tableau SDK: this would result in quite some overhead...
Writing a Dataflow job using a custom sink for Tableau Server (data extracts).
Experimenting with a Tableau web connector that communicates directly with the BigQuery API: I don't think this will be faster? I didn't see anything about parallelizing calls with the Tableau web connecector, but I didn't try this approach yet.
We would prefer a non-technical option, to limit maintenance... Is there a way to modify the Tableau connector to make use of the "daisy chain" option for BigQuery?
You've uploaded the data in BigQuery. Can't you just use the input for that load job (a CSV perhaps) as input for Tableau?
When we use Tableau and BigQuery we also notice that extracts are slow but we generally don't do that because you lose BigQuery's power. We start with a live data connection at first, and then (if needed) convert this into a custom query that aggregates that data into a much smaller datasets which extracts in just a few seconds.
Another way to achieve higher performance with BigQuery and Tableau is aggregating or joining tables on beforehand. JOINs on huge tables can be slow, so if you use a lot of those you might consider generating a denormalised dataset which does all of the JOIN-ing first. You will get a dataset with a lot of duplicates and a lot of columns. But if you select only what you need in Tableau (hide unused fields!) then these columns won't count in your query cost.
One recommendation I have seen is similar to your point 2 where you export the BQ table to Google Cloud Storage and then use the Tableau Extract API to create a .tde from the flat files in GCS.
This was from an article on the Google Cloud site so I'd assume it would be best practice:
https://cloud.google.com/blog/products/gcp/the-switch-to-self-service-marketing-analytics-at-zulily-best-practices-for-using-tableau-with-bigquery
There is an article here which provides a step by step guide to achieving the above.
https://community.tableau.com/docs/DOC-23161
It would be nice if Tableau optimised the BQ connector for extract refresh using the BigQuery Storage API. We too have our Tableau Server environment in the same GCP zone as our BQ datasets and experience slow refresh times.