[SPARK-12232][SPARKR] New R API for read.table to avoid name conflict

[felixcheung]

@shivaram sorry it took longer to fix some conflicts, this is the change to add an alias for table

[SparkQA]

Test build #48090 has finished for PR 10406 at commit 2e4b090.

• This patch passes all tests.
• This patch merges cleanly.
• This patch adds no public classes.

[sun-rui]

How about "tableToDF" ? there are some API methods having table in their names, like "createExternalTable", "saveAsTable", "tables". "tableToDF" is shorter and consistent.

[felixcheung]

I'm not sure - table in R generally is associated with data.frame (think read.table) or the popular data.table, I actually think saveAsTable and tables should be updated for clarity as well.

[felixcheung]

@shivaram @sun-rui any thought on this?

[sun-rui]

IMO, In the context of Spark, table means SQL table. Now that we have so many existing APIs using table in their names, as a new API, it is better to be consistent.

[shivaram]

Sorry for the delay in getting back on this - I agree that using table to refer to SQL table is probably fine. Also since this will go into 2.0 we can probably remove some of the old functions like tables instead of marking them as deprecated ?

[felixcheung]

Sure - I think we are saying this should be called tableToDF. What about tables, saveToTable, cacheTable, dropTempTable, or tableNames?

[shivaram]

So tableToDF actually sounds good to me and its fine to assume that somebody using SparkR thinks of table as a SQL table, so saveToTable, dropTempTable etc. sound fine to me.

We should definitely remove table which conflicts with base R and is completely unrelated. As for tables I'm also inclined to remove it especially if tableNames returns the same thing. Anyway you can open a new JIRA for discussing the rename / removal as well.

[felixcheung]

right.. tables is returning a DataFrame whereas tableNames is returning a vector? I'll open a JIRA to discuss these two.

For this, are we ok to remove table now, instead of .Deprecate I have here?

[shivaram]

Yes - removing table is fine.

[shivaram]

We should make a note in the release notes / deprecation from 1.x to 2.0 list somewhere as well
cc @rxin

[felixcheung]

There's the migration guide: http://spark.apache.org/docs/latest/sparkr.html#migration-guide

[felixcheung]

Done, updated code, tests, and doc.

[shivaram]

Thanks. LGTM. I'll just keep this open for a few hours to see if @sun-rui has any comments

[SparkQA]

Test build #49746 has finished for PR 10406 at commit 42b5af7.

• This patch passes all tests.
• This patch merges cleanly.
• This patch adds no public classes.

[sun-rui]

LGTM