Hello, Stuart. Can you do some research and find out how schema is handled in Data Frames for a regular RDBMS such as Oracle, MySQL, etc?
В Пн, 20/08/2018 в 15:37 -0700, Valentin Kulichenko пишет: > Stuart, Nikolay, > > I see that the 'Table' class (returned by listTables method) has a 'database' > field. Can we use this one to report schema name? > > In any case, I think we should look into how this is done in data source > implementations for other databases. Any relational database has a notion of > schema, and I'm sure Spark integrations take this into account somehow. > > -Val > > On Mon, Aug 20, 2018 at 6:12 AM Nikolay Izhikov <nizhi...@apache.org> wrote: > > Hello, Stuart. > > > > Personally, I think we should change current tables naming and return table > > in form of `schema.table`. > > > > Valentin, could you share your opinion? > > > > > > В Пн, 20/08/2018 в 10:04 +0100, Stuart Macdonald пишет: > > > Igniters, > > > > > > While reviewing the changes for IGNITE-9228 [1,2], Nikolay and I are > > > discussing whether to introduce a change which may impact backwards > > > compatibility; Nikolay suggested we take the discussion to this list. > > > > > > Ignite implements a custom Spark catalog which provides an API by which > > > Spark users can list the tables which are available in Ignite which can be > > > queried via Spark SQL. Currently that table name list includes just the > > > names of the tables, but IGNITE-9228 is introducing a change which allows > > > optional prefixing of schema names to table names to disambiguate multiple > > > tables with the same name in different schemas. For the "list tables" API > > > we therefore have two options: > > > > > > 1. List the tables using both their table names and schema-qualified table > > > names (eg. [ "myTable", "mySchema.myTable" ]) even though they are the > > > same > > > underlying table. This retains backwards compatibility with users who > > > expect "myTable" to appear in the catalog. > > > 2. List the tables using only their schema-qualified names. This > > > eliminates > > > duplication of names in the catalog but will potentially break > > > compatibility with users who expect the table name in the catalog. > > > > > > With either option we will allow for Spark SQL SELECT statements to use > > > either table name or schema-qualified table names, this change would > > > purely > > > impact the API which is used to list available tables. > > > > > > Any opinions would be welcome. > > > > > > Thanks, > > > Stuart. > > > > > > [1] https://issues.apache.org/jira/browse/IGNITE-9228 > > > [2] https://github.com/apache/ignite/pull/4551
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