> On May 3, 2016, 5:37 p.m., Ashutosh Chauhan wrote: > > ql/src/test/queries/clientpositive/create_with_constraints.q, line 19 > > <https://reviews.apache.org/r/46671/diff/4/?file=1369598#file1369598line19> > > > > Can you also add tests for describe formatted tblName colName; where > > colName is part of constraint. This should print out constraints relevant > > for that column. > > Hari Sankar Sivarama Subramaniyan wrote: > I dont see a reason why this should be allowed. This will make the column > details look complicated unnecessarily (for example, when there are multiple > foreign keys associated with the table column). Just printing out the partial > constraint information wont be of much use to the end user. Also, constraints > are not an entity of the column. Rather if the end-user wants to see the > constraints, he/she should do it on a table level. > > Ashutosh Chauhan wrote: > MySQL prints out what kind of constraint given column is a part of like > PK,FK,unique etc. Ref: https://dev.mysql.com/doc/refman/5.0/en/explain.html > Adding such an info for Hive will be useful.
I dont think we can include any option other than PRIMARY KEY since UNIQUE, MUL, etc are out of scope for this jira. Also, FOREIGN KEY cannot be shown because although its technically a key, it is a parent-child constraint relationship with bidirectional mapping (for e.g we can have PK which is also a FK, which one do we show in this scenario ?, also even if we mark a KEY field as a FK, it can be associated with multiple table columns and in this case just showing FK is of not much use to the end user). Below is the snippet from the documentation you have mentioned: The Key field indicates whether the column is indexed: If Key is empty, the column either is not indexed or is indexed only as a secondary column in a multiple-column, nonunique index. If Key is PRI, the column is a PRIMARY KEY or is one of the columns in a multiple-column PRIMARY KEY. If Key is UNI, the column is the first column of a UNIQUE index. (A UNIQUE index permits multiple NULL values, but you can tell whether the column permits NULL by checking the Null field.) If Key is MUL, the column is the first column of a nonunique index in which multiple occurrences of a given value are permitted within the column. - Hari Sankar ----------------------------------------------------------- This is an automatically generated e-mail. To reply, visit: https://reviews.apache.org/r/46671/#review131529 ----------------------------------------------------------- On May 3, 2016, 3:46 a.m., Hari Sankar Sivarama Subramaniyan wrote: > > ----------------------------------------------------------- > This is an automatically generated e-mail. To reply, visit: > https://reviews.apache.org/r/46671/ > ----------------------------------------------------------- > > (Updated May 3, 2016, 3:46 a.m.) > > > Review request for hive and Ashutosh Chauhan. > > > Repository: hive-git > > > Description > ------- > > Describe extended table should show the primary keys/foreign keys associated > with the table > > > Diffs > ----- > > itests/util/src/main/java/org/apache/hadoop/hive/ql/QTestUtil.java a6e8efa > metastore/scripts/upgrade/derby/034-HIVE-13076.derby.sql b062c56 > metastore/scripts/upgrade/derby/hive-schema-2.1.0.derby.sql 1d00499 > metastore/scripts/upgrade/mssql/019-HIVE-13076.mssql.sql 00ddb73 > metastore/scripts/upgrade/mssql/hive-schema-2.1.0.mssql.sql 2d9cf76 > metastore/scripts/upgrade/mysql/034-HIVE-13076.mysql.sql c9a5e1d > metastore/scripts/upgrade/mysql/hive-schema-2.1.0.mysql.sql 466e950 > metastore/scripts/upgrade/oracle/034-HIVE-13076.oracle.sql baf855c > metastore/scripts/upgrade/oracle/hive-schema-2.1.0.oracle.sql f57e588 > metastore/scripts/upgrade/postgres/033-HIVE-13076.postgres.sql ec1fb48 > metastore/scripts/upgrade/postgres/hive-schema-2.1.0.postgres.sql e209489 > metastore/src/java/org/apache/hadoop/hive/metastore/MetaStoreDirectSql.java > 744512f > metastore/src/java/org/apache/hadoop/hive/metastore/ObjectStore.java > f651a13 > metastore/src/model/org/apache/hadoop/hive/metastore/model/MConstraint.java > 3806e28 > metastore/src/model/package.jdo b40df39 > ql/src/java/org/apache/hadoop/hive/ql/exec/DDLTask.java 39a1efc > ql/src/java/org/apache/hadoop/hive/ql/metadata/ForeignKeyInfo.java > PRE-CREATION > ql/src/java/org/apache/hadoop/hive/ql/metadata/Hive.java 4d9c3d2 > ql/src/java/org/apache/hadoop/hive/ql/metadata/PrimaryKeyInfo.java > PRE-CREATION > > ql/src/java/org/apache/hadoop/hive/ql/metadata/formatting/JsonMetaDataFormatter.java > 75c2dd9 > > ql/src/java/org/apache/hadoop/hive/ql/metadata/formatting/MetaDataFormatter.java > 55e1b3b > > ql/src/java/org/apache/hadoop/hive/ql/metadata/formatting/TextMetaDataFormatter.java > b5dc0b4 > ql/src/test/queries/clientpositive/create_with_constraints.q eef0c64 > ql/src/test/results/clientpositive/create_with_constraints.q.out 5cf8d83 > > Diff: https://reviews.apache.org/r/46671/diff/ > > > Testing > ------- > > > Thanks, > > Hari Sankar Sivarama Subramaniyan > >
