arina-ielchiieva commented on a change in pull request #1807: DRILL-7293: Convert the regex ("log") plugin to use EVF URL: https://github.com/apache/drill/pull/1807#discussion_r293692425
########## File path: exec/java-exec/src/main/java/org/apache/drill/exec/store/log/README.md ########## @@ -129,19 +129,62 @@ Drill 1.16 introduced the `CREATE SCHEMA` command to allow you to define the schema for your table. This plugin was created earlier. Here is how the two schema systems interact. +### Plugin Config Provides Regex and Field Names + +The first way to use the provided schema is just to define column types. +In this use case, the plugin config provides the physical layout (pattern +and column names), the provided schema provides data types and default +values (for missing columns.) + +In this case: + * The plugin config must provide the regex. -* The plugin config should provide the list of column names. (If not provided, +* The plugin config provides the list of column names. (If not provided, the names will be `field_1`, `field_2`, etc.) -* The plugin config can provide a type for each field. Text data from the regex -is converted to a nullable column of the specified type. -* The table can provide a schema via `CREATE SCHEMA`. If so, the column names -in the schema must match those in the plugin config. The types in the provided -schema are used instead of those specified in the plugin config. The schema +* The plugin config should not provide column types. +* The table provides a schema via `CREATE SCHEMA`. Column names +in the schema must match those in the plugin config by name. The types in the +provided schema are used instead of those specified in the plugin config. The schema allows you to specify the data type, and either nullable or `not null` cardinality. -You may find it helpful to specify the regex and column names via the plugin -config, types via the `CREATE SCHEMA` command. +### Provided Schema Provides The Regex + +Another way to use the provided schema is to define an empty plugin config; don't +even provide the regex. Use table properties to define the regex (and the maximum +error count, if desired.) + +In this case: + +* Set the table property `drill.regex.regex` to the desired pattern. Review comment: I think we should use different naming, `drill.regex.regex` look awkward. Maybe `drill.regex.pattern` or something like this? ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: us...@infra.apache.org With regards, Apache Git Services