My Application's data is stored in both MongoDB and MYSQL. Is there any way to write queries in Metabase that will help in fetching data from both MYSQL and Mongo Databases?
I'm assuming here that by "My application's data" you are refering to the data sources, not to the Metabase internal databasa (aka metadata).
As of now (0.32.10), there is no way to query data from two different data sources.
What you can do, though, is to setup two (or more, depending on your need) different questions, and add them to a dashboard - that way, you will be able to show the data in a "data source agnostic" way.
If I didn't not get it wrong, I think this will be somewhat possible in the incoming version (0.33), scheduled for the next weeks (I believe), using the new join system (which will allow you to join data from different data sources, given a certain common key - say, "order_id" or something like that).
You can get more info, and even test the new version (which is currently in the RC2) at
this link.
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Intro
I've searched all around about this problem, but I didn't really found a source of knowledge about this, so I'm sorry if this problem seems basic to you, but for me is rather quite intriguing due the fact that I'm having hard time to guess what keywords to use on google in order to retrieve proper info.
Problem Description :
As a matter of fact, i have to issues that i don't know how to deal in a MySQL instance installed in a laptop in a windows environment:
I have a DB in MySQL with 50 tables, of with 15 or 20 tables are tables with original data. The other tables were tables that i generated from the original data tables, in order to properly create tables that would allow me to analyze data in PowerBI. The original data tables are fed by dumps from a ERP Database.
My issue is the following:
How would one automate the process of receiving cumulative txt/csv files (via pen-drive or any other transfer mechanism), store those files into a folder and then update the existing tables with the new information? Is there any reference of best practices to deal with such a scenario?
How can i maintain the good shape of my database with the successive data integration, I mean, how can I make my database scalable and responsive?
Can you point me some sources that would help me with this?
At the moment I imported data into tables, in 2 steps:
1st - I created the table structure with the Workbench import wizard help ( I had to do it this way because the tables have a lot of fields - dozens of them, literally, and those fields need to be in the database). I also inserted primary keys and indexes in those tables;
2nd - I Managed to load the data from the files into those tables, using LOAD DATA IN FILE command.
Some of the fields of the tables created with the import wizard, were created as data type text, with is not necessary in this scenario. I would like to revert those fields to data type NVARCHAR(255) or something, However there are a lot of field to alter the data type and in multiple tables at this point, and i was wondering if i can write a query to do the job of creating all the ALTER TABLES statements i need.
So my issue here is: is it safe to alter the data type in multiple fields in multiple columns (in this case i would like to change fields with datatype text to NAVARCHAR(255))? What is the best way to do this? Can you point me to some sources or best practices for this, please?
Thank you, in advance, for your help.
Cheers
You need a scripting language, not a UI. See mysql commandline tool, the shell of your OS, etc, etc.
DROP DATABASE and reCREATE it
LOAD DATA
Massage the data to get the columns cleaner than what the load data provided
Sic the BI tool on the data.
If you want to discuss Step 3, we need details about what transformations are needed between step 2 and step 4. That includes providing the format or schema for steps 2 and 4.
I am using Pentaho Data Integration Software.
I am currently running a Pentaho Job as an ETL. I ETL data from multiple places and put them into a single database table. The schema for all of the places i ETL from are exactly the same. So, other than database connections and a single 'variable' that stores where that data came from, the transformation in Pentaho is exactly the same for each one. So i have a job, that runs each of these transformation.
The problem comes in, when i want to make a change. I need to change 6 transformations every time. What i want to do, is somehow set something like a variable in Pentaho, that tells it to run a single transformation, 6 times, with different database connections, and perhaps a single variable.
Is this possible?
Thanks in advanced.
If i have understood your question correctly, you need to loop multiple transformations using a single KTR file (assuming there is only one database type).
PDI provides you with a step called "Copy Rows to Result", where you can store the credentials of your database in multiple rows and for every run of the Job, it will use different connections and run the transformation multiple times (6 in ur case).
Note: I have assumed that you are having only one database type e.g. : mySQL but with different credentials.
Hope this helps :) I would be happy to provide you sample code in case you need it.
Well, why don't you use a job that will pass the host/user/password as variables? That way your whole data flow will be generic.
Hope this answer will lead you into the right direction!
I got indexed a Mysql database using Solr and everything is perfect. Now i got another database which uses exactly the same schema as my first database but with different data in it.
What i want is to use Solr to index also the second database using the same solr schema that i created for my first database since are completely the same!
I read that Solr cores allows you to run multiple instances that use different configuration sets and indexes, but in my case i got the same exactly configuration, the only thing that changes is the database name.
My question is what is the best way two create two Solr instances that use the same configuration?
Cheers
You could use two cores and share a schema. Just read the Wiki. But in practice you might want to keep the flexibility and just copy the schema for a second core.
How about using only one solr instance but have a field in the schema that contains a value which indicates which db/source the record came from.
I am very new to this and a good friend is in a bind. I am at my wits end. I have used gui's like navicat and sqlyog to do this but, only manually.
His band info data (schedules and whatnot) is in a MYSQL database on a server (admin server).
I am putting together a basic site for him written in Perl that grabs data from a database that resides on my server (public server) and displays schedule info, previous gig newsletters and some fan interaction.
He uses an administrative interface, which he likes and desires to keep, to manage the data on the admin server.
The admin server db has a bunch of tables and even table data the public db does not need.
So, I created tables on the public side that only contain relevant data.
I basically used a gui to export the data, then insert to the public side whenever he made updates to the admin db (copy and paste).
(FYI I am using DBI module to access the data in/via my public db perl script.)
I could access the admin server directly to grab only the data I need but, the whole purpose of this is to "mirror" the data not access the admin server on every query. Also, some tables are THOUSANDS of rows and parsing every row in a loop seemed too "bulky" to me. There is however a "time" column which could be utilized to compare to.
I cannot "sync" due to the fact that the structures are different, I only need the relevant table data from only three tables.
SO...... I desire to automate!
I read "copy" was a fast way but, my findings in how to implement were too advanced for my level.
I do not have the luxury of placing a script on the admin server to notify when there was an update.
1- I would like to set up a script to check a table to see if a row was updated or added on the admin servers db.
I would then desire to update or insert the new or changed data to the public servers db.
This "check" could be set up in a cron job I guess or triggered when a specific page loads on the public side. (the same sub routine called by the cron I would assume).
This data does not need to be "real time" but, if he updates something it would be nice to have it appear as quickly as possible.
I have done much reading, module research and experimenting but, here I am again at stackoverflow where I always get great advice and examples.
Much of the terminology is still quite over my head so verbose examples with explanations really help me learn quicker.
Thanks in advance.
The two terms you are looking for are either "replication" or "ETL".
First, replication approach.
Let's assume your admin server has tables T1, T2, T3 and your public server has tables TP1, TP2.
So, what you want to do (since you have different table structres as you said) is:
Take the tables from public server, and create exact copies of those tables on the admin server (TP1 and TP2).
Create a trigger on the admin server's original tables to populate the data from T1/T2/T3 into admin server's copy of TP1/TP2.
You will also need to do initial data population from T1/T2/T3 into admin server's copy of TP1/TP2. Duh.
Set up the "replication" from admin server's TP1/TP2 to public server's TP1/TP2
A different approach is to write a program (such programs are called ETL - Extract-Transform-Load) which will extract the data from T1/T2/T3 on admin server (the "E" part of "ETL"), massage the data into format suitable for loading into TP1/TP2 tables (the "T" part of "ETL"), transfer (via ftp/scp/whatnot) those files to public server, and the second half of the program (the "L") part will load the files into the tables TP1/TP2 on public server. Both halfs of the program would be launched by cron or your scheduler of choice.
There's an article with a very good example of how to start building Perl/MySQL ETL: http://oreilly.com/pub/a/databases/2007/04/12/building-a-data-warehouse-with-mysql-and-perl.html?page=2
If you prefer not to build your own, here's a list of open source ETL systems, never used any of them so no opinions on their usability/quality: http://www.manageability.org/blog/stuff/open-source-etl
I think you've misunderstood ETL as a problem domain, which is complicated, versus ETL as a one-off solution, which is often not much harder than writing a report. Unless I've totally misunderstood your problem, you don't need a general ETL solution, you need a one-off solution that works on a handful of tables and a few thousand rows. ETL and Schema mapping sound scarier than they are for a single job. (The generalization, scaling, change-management, and OLTP-to-OLAP support of ETL are where it gets especially difficult.) If you can use Perl to write a report out of a SQL database, you probably know enough to handle the ETL involved here.
1- I would like to set up a script to check a table to see if a row was updated or added on the admin servers db. I would then desire to update or insert the new or changed data to the public servers db.
If every table you need to pull from has an update timestamp column, then your cron job includes some SELECT statements with WHERE clauses based on the last time the cron job ran to get only the updates. Tables without an update timestamp will probably need a full dump.
I'd use a one-to-one table mapping unless normalization was required... just simpler to my opinion. Why complicate it with "big" schema changes if you don't have to?
some tables are THOUSANDS of rows and parsing every row in a loop seemed too "bulky" to me.
Limit your queries to only the columns you need (and if there are no BLOBs or exceptionally big columns in what you need) a few thousand rows should not be a problem via DBI with a FETCHALL method. Loop all you want locally, just make as few trips to the remote database as possible.
If a row is has a newer date, update it. I will also have to check for new rows for insertion.
Each table needs one SELECT ... WHERE updated_timestamp_columnname > last_cron_run_timestamp. That result set will contain all rows with newer timestamps, which contains newly inserted rows (if the timestamp column behaves like I'd expect). For updating your local database, check out MySQL's ON DUPLICATE KEY UPDATE syntax... this will let you do it in one step.
... how to implement were too advanced for my level ...
Yes, I have actually done this already but, I have to manually update...
Some questions to help us understand your level... Are you hitting the database from the mysql client command-line or from a GUI? Have you gotten to the point where you've wrapped your SQL queries in Perl and DBI, yet?
If the two databases have different, you'll need an ETL solution to map from one schema to another.
If the schemas are the same, all you have to do is replicate the data from one to the other.
Why not just create identical structure on the 'slave' server to the master server. Then create a small table that keeps track of the last timestamp or id for the updated tables.
Then select from the master all rows changed since the last timestamp or greater than the id. Insert them into the matching table on the slave server.
You will need to be careful of updated rows. If a row on the master is updated but the timestamp doesn't change then how will you tell which rows to fetch? If that's not an issue the process is quite simple.
If it is an issue then you need to be more sophisticated, but without knowing the data structure and update mechanism its a goose chase to give pointers on it.
The script could be called by cron every so often to update the changes.
if the database structures must be different on the two servers then a simple translation step may need to be added, but most of the time that can be done within the sql select statement and maybe a join or two.
I need to convert data that already exists in a MySQL database, to a SQL Server database.
The caveat here is that the old database was poorly designed, but the new one is in a proper 3N form. Does any one have any tips on how to go about doing this? I have SSMS 2005.
Can I use this to connect to the MySQL DB and create a DTS? Or do I need to use SSIS?
Do I need to script out the MySQL DB and alter every statement to "insert" into the SQL Server DB?
Has anyone gone through this before? Please HELP!!!
See this link. The idea is to add your MySQL database as a linked server in SQL Server via the MySQL ODBC driver. Then you can perform any operations you like on the MySQL database via SSMS, including copying data into SQL Server.
Congrats on moving up in the RDBMS world!
SSIS is designed to do this kind of thing. The first step is to map out manually where each piece of data will go in the new structure. So your old table had four fields, in your new structure fileds1 and 2 go to table a and field three and four go to table b, but you also need to have the autogenerated id from table a. Make notes as to where data types have changed and you may need to make adjustments or where you have required fileds where the data was not required before etc.
What I usually do is create staging tables. Put the data in the denormalized form in one staging table and then move to normalized staging tables and do the clean up there and add the new ids as soon as you have them to the staging tables. One thing you will need to do if you are moving from a denormalized database to a normalized one is that you will need to eliminate the duplicates from the parent tables before inserting them into the actual production tables. You may also need to do dataclean up as there may be required fileds in the new structure that were not required in the old or data converstion issues becasue of moving to better datatypes (for instance if you stored dates in the old database in varchar fields but properly move to datetime in the new db, you may have some records which don't have valid dates.
ANother issue you need to think about is how you will convert from the old record ids to the new ones.
This is not a an easy task, but it is doable if you take your time and work methodically. Now is not the time to try shortcuts.
What you need is an ETL (extract, transform, load) tool.
http://en.wikipedia.org/wiki/Extract,_transform,_load#Tools
I don't really know how far an 'ETL' tool will get you depending on the original and new database designs. In my career I've had to do more than a few data migrations and we usually always had to design a special utility which would update a fresh database with records from the old database, and yes we coded it complete with all the update/insert statements that would transform data.
I don't know how many tables your database has, but if they are not too many then you could consider going the grunt root. That's one technique that's guaranteed to work after all.
If you go to your database in SSMS and right-click, under tasks should be an option for "Import Data". You can try to use that. It's basically just a wizard that creates an SSIS package for you, which it can then either run for you automatically or which you can save and then alter as needed.
The big issue is how you need to transform the data. This goes into a lot of specifics which you don't include (and which are probably too numerous for you to include here anyway).
I'm certain that SSIS can handle whatever transformations you need to do to change it from the old format to the new. An alternative though would be to just import the tables into MS SQL as-is into staging tables, then use SQL code to transform the data into the 3NF tables. It's all a matter of what your most comfortable with. If you go the second route, then the import process that I mentioned above in SSMS could be used. It will even create the destination tables for you. Just be sure that you give them unique names, maybe prefixing them with "STG_" or something.
Davud mentioned linked servers. That's definitely another way that you can go (and got my upvote). Personally, I prefer to copy the tables over into MS SQL first since linked servers can sometimes have weirdness, especially when it comes to data types not mapping between different providers. Having the tables all in MS SQL will also probably be a bit faster and saves time if you have to rerun or correct portions of the data. As I said though, the linked server method would probably be fine too.
I have done this going the other direction and SSIS works fine, although I might have needed to use a script task to deal with slight data type weirdness. SSIS does ETL.