If you'd like to contribute a patch to Impala, but aren't sure what you want to work on, you can look at Impala's newbie issues: https://issues.apache.org/jira/issues/?filter=12341668. You can find detailed instructions on submitting patches at https://cwiki.apache.org/confluence/display/IMPALA/Contributing+to+Impala. This is a walkthrough of a ticket a new contributor could take on, with hopefully enough detail to get you going but not so much to take away the fun.
How can we fix https://issues.apache.org/jira/browse/IMPALA-5314, "Rename single letter tables in FE tests"? First, get your development environment set up. Then, since this is a ticket about frontend ("FE") tests, you'll want to check that your frontend tests are passing. Following https://cwiki.apache.org/confluence/display/IMPALA/How+to+load+and+run+Impala+tests : (pushd fe && mvn -fae test) This particular ticket proposes to change single-letter table names to names less likely to collide with a developer's existing environment. Let's check to see what these look like. Run bin/impala-shell.sh and: [localhost:21000] > create table t (id int); Query: create table t (id int) Fetched 0 row(s) in 0.04s [localhost:21000] > create table p (id int); Query: create table p (id int) Fetched 0 row(s) in 0.03s Now run your frontend tests again. At the moment I am writing this, that causes 15 failures. Doing a very simple search-and-replace (using git ls-files and sed), I replaced " table p " and " table t " with " table JohnJacobJingleheimerSchmidt ", which reduced the number of failures to 11. This likely means that this simple method will help four tests could be made resilient to developer-created single-letter table names. Next, drop the tables t and p that you created above via bin/impala-shell.sh. Run the frontend tests again and carefully inspect the output. This will help you fix any tests broken by the simple search-and-replace. Once all the tests are passing again, you can send your patch for review following https://cwiki.apache.org/confluence/display/IMPALA/Contributing+to+Impala. Your patch doesn't have to fix the entirety of the ticket to be sent for review. It is probably good to get one patch under your belt before sending any large patches. One this patch is committed and in Impala, you can come back to this ticket and continue to fix single table names in future patches. One place you'll want to look for those is in testdata/workloads/functional-planner/queries/PlannerTest/*.test. These files are test data for use in fe/src/test/java/org/apache/impala/planner/*Test.java. For those, a more complex search-and-replace pattern will remove some issues, but it won't fix everything. Have fun!
