Redis Query Component

Redis Query

This component retrieves data from the Redis database and loads that data into a table. Doing this stages the data, so that the table is reloaded each time. After this, you can use transformations to enrich and manage the data in permanent tables.

The Redis Query component supports the following Redis Data Types:

  • Binary-safe Strings
  • Lists: collections of string elements sorted according to the order of insertion. They are basically linked lists.
  • Sets: collections of unique, unsorted string elements.
  • Sorted Sets (ZSets): similar to sets but where every string element is associated with a floating number value, called score. The elements are always sorted by their score, so unlike sets, it is possible to retrieve a range of elements.
  • Hashes: maps composed of fields associated with values. Both the field and the value are strings. This is very similar to Ruby or Python hashes.

Warning: This component is potentially destructive. If the target table undergoes a change in structure, it will be recreated. Otherwise, the target table is truncated. Setting the Load Option 'Recreate Target Table' to 'Off' will prevent both recreation and truncation. Do not modify the target table structure manually.

Properties

Property Setting Description
Name Text The descriptive name for the component.
Basic/Advanced Mode Choice Basic: This mode will build a query for you using the settings from the Data SourceData Selection, and Data Source Filter parameters. In most cases, this mode will be sufficient for your query.
Advanced: Using the Advanced mode will require you to write an SQL-like query to call data from Redis. The available fields and their descriptions are documented in the Redis Query data model.
Server Text The server IP or DNS address of the Redis server endpoint.
Password Choice or Text The login password for the Redis server. If the Redis server does not have a password set, this field can be left empty.
Users have the option to store their password inside the component; however, we highly recommend using the Password Manager feature instead.
Define Tables Multiple Selection This optional parameter allows you to customise your table results to your preference. You might choose to specify each key as a table, or group certain keys together based on a Key Pattern. For example:
Company=Company*

In this example, all keys labelled "Company" would be situated under a single table defined as "Company".

Note: If there was an individual key labelled "Company" then selection of this key would instead yield all "Company" keys as defined within the Define Tables parameter.
SQL Query Text This is an SQL-like SELECT query. Treat collections as table names, and fields as columns. (Property only available in Advanced Mode.)
Note: Any defined tables will appear within the Advanced Mode's SQL editor. However, individual keys will not (aside from the primary Keys table).
Data Source Select The Redis driver stores all Redis keys under a single table named "Keys". This is the data source.
Data Selection Choice Select one or more of the columns to return from the query. Columns are determined by scanning the first few documents and searching for fields that appear in each document. Nested fields are searched if Flatten Objects is set to Yes. Otherwise, nested documents become a single, larger string.
Data Source Filter Input Column The available input columns vary depending upon the Data Source and are determined automatically by scanning a number of documents.
Qualifier Is - Compares the column to the value using the comparator.
Not - Reverses the effect of the comparison, so "Equals" becomes "Not equals", "Less than" becomes "Greater than or equal to", etc.
Comparator Choose a method of comparing the column to the value. Possible comparators include: "Equal to", "Greater than", "Less than", "Greater than or equal to", "Less than or equal to", "Like", "Is Null".
"Equal to" can match exact strings and numeric values while other comparators, such as "Greater than", will work only with numerics. The "Like" operator allows the wildcard character (%) to be used at the start and end of a string value to match a column. The Is Null operator matches only Null values, ignoring whatever the value is set to.
Note: Not all data sources support all comparators, meaning that it is likely that only a subset of the above comparators will be available to choose from.
Value The value to be compared.
Combine Filters Text Use the defined filters in combination with one another according to either "and" or "or".
Limit Number Limits the number of rows that are loaded.
Connection Options Parameter A JDBC parameter supported by the Database Driver. The available parameters are determined automatically from the driver, and may change from version to version.
They are usually not required, since sensible defaults are assumed.
Value A value for the given parameter.
Warehouse Select Choose a Snowflake warehouse that will run the load.
Database Select Choose a database to create the new table in.
Type Select Choose between using a standard table or an external table.
Standard: The data will be staged on an S3 bucket before being loaded into a table.
External: The data will be put into an S3 Bucket and referenced by an external table.
Schema Select Select the table schema. The special value (Environment Default) will use the schema defined in the environment. For more information on using multiple schemas, see this article.
Note: An external schema is required if the 'Type' property is set to 'External'.
Project Text The target BigQuery project to load data into.
Dataset Text The target BigQuery dataset to load data into.
Target Table Text Provide a new table name.
Warning: This table will be recreated and will drop any existing table of the same name.
Table Text Provide a new table name.
Warning: This table will be recreated and will drop any existing table of the same name.
Staging Select (AWS Only) Snowflake Managed: Allow Matillion ETL to create and use a temporary internal stage on Snowflake for staging the data. This stage, along with the staged data, will cease to exist after loading is complete.
Existing Amazon S3 Location: Selecting this will avail the user of properties to specify a custom staging area on S3.
S3 Staging Area Text (AWS Only) The name of an S3 bucket for temporary storage. Ensure your access credentials have S3 access, as well as permission to write to the bucket. See this document for details on setting up access. The temporary objects created in this bucket will be removed again after the load completes, they are not kept.
This property is available when using an Existing Amazon S3 Location for Staging.
Cloud Storage Staging Area Text The URL and path of the target Google Storage bucket to be used for staging the queried data.
Distribution Style Select Even - this is the default option. It distributes rows around the Redshift Cluster evenly.
All - this copies rows to all nodes in the Redshift Cluster.
Key - this distributes rows around the Redshift cluster according to the value of a key column.
Table-distribution is critical to good performance - see the Amazon Redshift documentation for more information.
Sort Key Select This is optional, and specifies the columns from the input that should be set as the table's sort key.
Sort keys are critical to good performance - see the Amazon Redshift documentation for more information.
Sort Key Options Select Decide whether the sort key is of a compound or interleaved variety - see the Amazon Redshift documentation for more information.
Load Options Multiple Selection Comp Update: Apply automatic compression to the target table (if ON). Default is ON.
Stat Update: Automatically update statistics when filling a table (if ON). Default is ON. In this case, it is updating the statistics of the target table.
Clean S3 Objects: Automatically remove UUID-based objects on the S3 Bucket (if ON). Default is ON. Effectively decides whether to keep the staged data in the S3 Bucket or not.
String Null is Null: Converts any strings equal to "null" into a null value. This is case sensitive and only works with entirely lower-case strings. Default is OFF.
Recreate Target Table: Choose whether the component recreates its target table before the data load. If OFF, the existing table will be used. Default is ON.
File Prefix: Give staged file names a prefix of your choice. Default is empty (no prefix).
Load Options Choice & Text Clean Staged Files: Destroy staged files after loading data. Default is ON.
String Null is Null: Converts any strings equal to "null" into a null value. This is case sensitive and only works with entirely lower-case strings. Default is OFF.
Recreate Target Table: Choose whether the component recreates its target table before the data load. If OFF, the existing table will be used. Default is ON.
File Prefix: Give staged file names a prefix of your choice. Default is empty (no prefix).
Trim String Columns: Choose whether to remove leading and trailing characters from a string column.
Use Grid Variable: Check this checkbox to use a grid variable.
Load Options Multiple Select Clean Cloud Storage Files: (If On) Destroy staged files on Cloud Storage after loading data. Default is ON.
Cloud Storage File Prefix: Give staged file names a prefix of your choice. Default is empty (no prefix).
Recreate Target Table: Choose whether the component recreates its target table before the data load. If OFF, the existing table will be used. Default is ON.
Use Grid Variable: Check this checkbox to use a grid variable.
Encryption Select (AWS Only) Decide on how the files are encrypted inside the S3 Bucket. This property is available when using an Existing Amazon S3 Location for Staging.
None: No encryption.
SSE KMS: Encrypt the data according to a key stored on KMS.
SSE S3: Encrypt the data according to a key stored on an S3 bucket
KMS Key ID Select (AWS Only) The ID of the KMS encryption key you have chosen to use in the 'Encryption' property.
Auto Debug Select Choose whether to automatically log debug information about your load. These logs can be found in the Task History and should be included in support requests concerning the component. Turning this on will override any debugging Connection Options.
Debug Level Select The level of verbosity with which your debug information is logged. Levels above 1 can log huge amounts of data and result in slower execution.
1: Will log the query, the number of rows returned by it, the start of execution and the time taken, and any errors.
2: Will log everything included in Level 1, plus cache queries and additional information about the request, if applicable.
3: Will additionally log the body of the request and the response.
4: Will additionally log transport-level communication with the data source. This includes SSL negotiation.
5: Will additionally log communication with the data source, as well as additional details that may be helpful in troubleshooting problems. This includes interface commands.

Variable Exports

This component makes the following values available to export into variables:

Source Description
Time Taken To Stage The amount of time (in seconds) taken to fetch the data from the data source and to upload it to storage.
Time Taken To Load The amount of time (in seconds) taken for the COPY statement to load the data into the target table from the staging area.

Strategy

Connect to the Redis server and issue the one or more queries. Stream the results into objects into a storage area, then recreate or truncate the target table as necessary. Then, use a COPY command to load the stored objects into the table. Finally, clean up the temporary stored objects.