HIVE-1078. CREATE VIEW followup: CREATE OR REPLACE (Charles Chen via …

…jvs)

git-svn-id: https://svn.apache.org/repos/asf/hive/trunk@1149727 13f79535-47bb-0310-9956-ffa450edef68

metastore/src/java/org/apache/hadoop/hive/metastore/HiveAlterHandler.java

@@ -30,9 +30,9 @@
 import org.apache.hadoop.hive.metastore.api.InvalidObjectException;
 import org.apache.hadoop.hive.metastore.api.InvalidOperationException;
 import org.apache.hadoop.hive.metastore.api.MetaException;
+import org.apache.hadoop.hive.metastore.api.NoSuchObjectException;
 import org.apache.hadoop.hive.metastore.api.Partition;
 import org.apache.hadoop.hive.metastore.api.Table;
-import org.apache.hadoop.hive.metastore.api.NoSuchObjectException;
 
 /**
  * Hive specific implementation of alter
@@ -97,11 +97,13 @@ public void alterTable(RawStore msdb, Warehouse wh, String dbname,
             + newt.getTableName() + " doesn't exist");
       }
 
-      // check that partition keys have not changed
-      if (oldt.getPartitionKeys().size() != newt.getPartitionKeys().size()
-          || !oldt.getPartitionKeys().containsAll(newt.getPartitionKeys())) {
-        throw new InvalidOperationException(
-            "partition keys can not be changed.");
+      // check that partition keys have not changed, except for virtual views
+      if(!oldt.getTableType().equals(TableType.VIRTUAL_VIEW.toString())){
+        if (oldt.getPartitionKeys().size() != newt.getPartitionKeys().size()
+            || !oldt.getPartitionKeys().containsAll(newt.getPartitionKeys())) {
+          throw new InvalidOperationException(
+              "partition keys can not be changed.");
+        }
       }
 
       // if this alter is a rename, the table is not a virtual view, the user

metastore/src/java/org/apache/hadoop/hive/metastore/ObjectStore.java

@@ -1664,6 +1664,8 @@ public void alterTable(String dbname, String name, Table newTable)
       oldt.setPartitionKeys(newt.getPartitionKeys());
       oldt.setTableType(newt.getTableType());
       oldt.setLastAccessTime(newt.getLastAccessTime());
+      oldt.setViewOriginalText(newt.getViewOriginalText());
+      oldt.setViewExpandedText(newt.getViewExpandedText());
 
       // commit the changes
       success = commitTransaction();

ql/src/java/org/apache/hadoop/hive/ql/exec/DDLTask.java

@@ -3369,31 +3369,70 @@ private int createTableLike(Hive db, CreateTableLikeDesc crtTbl) throws HiveExce
    *           Throws this exception if an unexpected error occurs.
    */
   private int createView(Hive db, CreateViewDesc crtView) throws HiveException {
-    Table tbl = db.newTable(crtView.getViewName());
-    tbl.setTableType(TableType.VIRTUAL_VIEW);
-    tbl.setSerializationLib(null);
-    tbl.clearSerDeInfo();
-    tbl.setViewOriginalText(crtView.getViewOriginalText());
-    tbl.setViewExpandedText(crtView.getViewExpandedText());
-    tbl.setFields(crtView.getSchema());
-    if (crtView.getComment() != null) {
-      tbl.setProperty("comment", crtView.getComment());
-    }
-    if (crtView.getTblProps() != null) {
-      tbl.getTTable().getParameters().putAll(crtView.getTblProps());
-    }
+    Table oldview = db.getTable(crtView.getViewName(), false);
+    if (crtView.getOrReplace() && oldview != null) {
+      // replace existing view
+      if (!oldview.getTableType().equals(TableType.VIRTUAL_VIEW)) {
+        throw new HiveException("Existing table is not a view");
+      }
+
+      if (crtView.getPartCols() == null
+          || crtView.getPartCols().isEmpty()
+          || !crtView.getPartCols().equals(oldview.getPartCols())) {
+        // if we are changing partition columns, check that partitions don't exist
+        if (!oldview.getPartCols().isEmpty() &&
+            !db.getPartitions(oldview).isEmpty()) {
+          throw new HiveException(
+              "Cannot add or drop partition columns with CREATE OR REPLACE VIEW if partitions currently exist");
+        }
+      }
 
-    if (crtView.getPartCols() != null) {
-      tbl.setPartCols(crtView.getPartCols());
-    }
+      // remove the existing partition columns from the field schema
+      oldview.setViewOriginalText(crtView.getViewOriginalText());
+      oldview.setViewExpandedText(crtView.getViewExpandedText());
+      oldview.setFields(crtView.getSchema());
+      if (crtView.getComment() != null) {
+        oldview.setProperty("comment", crtView.getComment());
+      }
+      if (crtView.getTblProps() != null) {
+        oldview.getTTable().getParameters().putAll(crtView.getTblProps());
+      }
+      oldview.setPartCols(crtView.getPartCols());
+      oldview.checkValidity();
+      try {
+        db.alterTable(crtView.getViewName(), oldview);
+      } catch (InvalidOperationException e) {
+        throw new HiveException(e);
+      }
+      work.getOutputs().add(new WriteEntity(oldview));
+    } else {
+      // create new view
+      Table tbl = db.newTable(crtView.getViewName());
+      tbl.setTableType(TableType.VIRTUAL_VIEW);
+      tbl.setSerializationLib(null);
+      tbl.clearSerDeInfo();
+      tbl.setViewOriginalText(crtView.getViewOriginalText());
+      tbl.setViewExpandedText(crtView.getViewExpandedText());
+      tbl.setFields(crtView.getSchema());
+      if (crtView.getComment() != null) {
+        tbl.setProperty("comment", crtView.getComment());
+      }
+      if (crtView.getTblProps() != null) {
+        tbl.getTTable().getParameters().putAll(crtView.getTblProps());
+      }
 
-    int rc = setGenericTableAttributes(tbl);
-    if (rc != 0) {
-      return rc;
-    }
+      if (crtView.getPartCols() != null) {
+        tbl.setPartCols(crtView.getPartCols());
+      }
 
-    db.createTable(tbl, crtView.getIfNotExists());
-    work.getOutputs().add(new WriteEntity(tbl));
+      int rc = setGenericTableAttributes(tbl);
+      if (rc != 0) {
+        return rc;
+      }
+
+      db.createTable(tbl, crtView.getIfNotExists());
+      work.getOutputs().add(new WriteEntity(tbl));
+    }
     return 0;
   }
 

ql/src/java/org/apache/hadoop/hive/ql/parse/Hive.g

@@ -200,6 +200,7 @@ TOK_LIMIT;
 TOK_TABLEPROPERTY;
 TOK_IFEXISTS;
 TOK_IFNOTEXISTS;
+TOK_ORREPLACE;
 TOK_HINTLIST;
 TOK_HINT;
 TOK_MAPJOIN;
@@ -370,6 +371,13 @@ ifNotExists
     -> ^(TOK_IFNOTEXISTS)
     ;
 
+orReplace
+@init { msgs.push("or replace clause"); }
+@after { msgs.pop(); }
+    : KW_OR KW_REPLACE
+    -> ^(TOK_ORREPLACE)
+    ;
+
 
 createDatabaseStatement
 @init { msgs.push("create database statement"); }
@@ -997,12 +1005,13 @@ createViewStatement
     msgs.push("create view statement");
 }
 @after { msgs.pop(); }
-    : KW_CREATE KW_VIEW ifNotExists? name=tableName
+    : KW_CREATE (orReplace)? KW_VIEW (ifNotExists)? name=tableName
         (LPAREN columnNameCommentList RPAREN)? tableComment? viewPartition?
         tablePropertiesPrefixed?
         KW_AS
         selectStatement
-    -> ^(TOK_CREATEVIEW $name ifNotExists?
+    -> ^(TOK_CREATEVIEW $name orReplace?
+         ifNotExists?
          columnNameCommentList?
          tableComment?
          viewPartition?

ql/src/java/org/apache/hadoop/hive/ql/parse/SemanticAnalyzer.java

@@ -195,6 +195,7 @@ public class SemanticAnalyzer extends BaseSemanticAnalyzer {
   Map<String, PrunedPartitionList> prunedPartitions;
   private List<FieldSchema> resultSchema;
   private CreateViewDesc createVwDesc;
+  private ArrayList<String> viewsExpanded;
   private ASTNode viewSelect;
   private final UnparseTranslator unparseTranslator;
   private final GlobalLimitCtx globalLimitCtx = new GlobalLimitCtx();
@@ -873,6 +874,7 @@ public void getMetaData(QB qb) throws SemanticException {
       // We have to materialize the table alias list since we might
       // modify it in the middle for view rewrite.
       List<String> tabAliases = new ArrayList<String>(qb.getTabAliases());
+      Map<String, String> aliasToViewName = new HashMap<String, String>();
       for (String alias : tabAliases) {
         String tab_name = qb.getTabNameForAlias(alias);
         Table tab = null;
@@ -911,7 +913,15 @@ public void getMetaData(QB qb) throws SemanticException {
           if (qb.getParseInfo().isAnalyzeCommand()) {
             throw new SemanticException(ErrorMsg.ANALYZE_VIEW.getMsg());
           }
+          String fullViewName = tab.getDbName()+"."+tab.getTableName();
+          // Prevent view cycles
+          if(viewsExpanded.contains(fullViewName)){
+            throw new SemanticException("Recursive view " + fullViewName +
+                " detected (cycle: " + StringUtils.join(viewsExpanded, " -> ") +
+                " -> " + fullViewName + ").");
+          }
           replaceViewReferenceWithDefinition(qb, tab, tab_name, alias);
+          aliasToViewName.put(alias, fullViewName);
           continue;
         }
 
@@ -940,8 +950,15 @@ public void getMetaData(QB qb) throws SemanticException {
       LOG.info("Get metadata for subqueries");
       // Go over the subqueries and getMetaData for these
       for (String alias : qb.getSubqAliases()) {
+        boolean wasView = aliasToViewName.containsKey(alias);
+        if (wasView) {
+          viewsExpanded.add(aliasToViewName.get(alias));
+        }
         QBExpr qbexpr = qb.getSubqForAlias(alias);
         getMetaData(qbexpr);
+        if (wasView) {
+           viewsExpanded.remove(viewsExpanded.size()-1);
+        }
       }
 
       LOG.info("Get metadata for destination tables");
@@ -7124,6 +7141,7 @@ public void analyzeInternal(ASTNode ast) throws SemanticException {
     this.qb = qb;
     this.ast = ast;
     ASTNode child = ast;
+    viewsExpanded = new ArrayList<String>();
 
     LOG.info("Starting Semantic Analysis");
 
@@ -7145,6 +7163,8 @@ public void analyzeInternal(ASTNode ast) throws SemanticException {
         return;
       }
       viewSelect = child;
+      // prevent view from referencing itself
+      viewsExpanded.add(db.getCurrentDatabase()+"."+createVwDesc.getViewName());
     }
 
     // continue analyzing from the child ASTNode.
@@ -7778,6 +7798,7 @@ private ASTNode analyzeCreateView(ASTNode ast, QB qb)
     String tableName = getUnescapedName((ASTNode)ast.getChild(0));
     List<FieldSchema> cols = null;
     boolean ifNotExists = false;
+    boolean orReplace = false;
     String comment = null;
     ASTNode selectStmt = null;
     Map<String, String> tblProps = null;
@@ -7792,6 +7813,9 @@ private ASTNode analyzeCreateView(ASTNode ast, QB qb)
       case HiveParser.TOK_IFNOTEXISTS:
         ifNotExists = true;
         break;
+      case HiveParser.TOK_ORREPLACE:
+        orReplace = true;
+        break;
       case HiveParser.TOK_QUERY:
         selectStmt = child;
         break;
@@ -7812,8 +7836,12 @@ private ASTNode analyzeCreateView(ASTNode ast, QB qb)
       }
     }
 
+    if (ifNotExists && orReplace){
+      throw new SemanticException("Can't combine IF NOT EXISTS and OR REPLACE.");
+    }
+
     createVwDesc = new CreateViewDesc(
-      tableName, cols, comment, tblProps, partColNames, ifNotExists);
+      tableName, cols, comment, tblProps, partColNames, ifNotExists, orReplace);
     unparseTranslator.enable();
     rootTasks.add(TaskFactory.get(new DDLWork(getInputs(), getOutputs(),
         createVwDesc), conf));

ql/src/java/org/apache/hadoop/hive/ql/plan/CreateViewDesc.java

@@ -42,22 +42,24 @@ public class CreateViewDesc extends DDLDesc implements Serializable {
   private List<FieldSchema> partCols;
   private String comment;
   private boolean ifNotExists;
+  private boolean orReplace;
 
   /**
    * For serialization only.
    */
   public CreateViewDesc() {
   }
-  
+
   public CreateViewDesc(String viewName, List<FieldSchema> schema,
       String comment, Map<String, String> tblProps,
-      List<String> partColNames, boolean ifNotExists) {
+      List<String> partColNames, boolean ifNotExists, boolean orReplace) {
     this.viewName = viewName;
     this.schema = schema;
     this.comment = comment;
     this.tblProps = tblProps;
     this.partColNames = partColNames;
     this.ifNotExists = ifNotExists;
+    this.orReplace = orReplace;
   }
 
   @Explain(displayName = "name")
@@ -147,4 +149,13 @@ public boolean getIfNotExists() {
   public void setIfNotExists(boolean ifNotExists) {
     this.ifNotExists = ifNotExists;
   }
+
+  @Explain(displayName = "or replace")
+  public boolean getOrReplace() {
+    return orReplace;
+  }
+
+  public void setOrReplace(boolean orReplace) {
+    this.orReplace = orReplace;
+  }
 }

ql/src/test/queries/clientnegative/create_or_replace_view1.q

@@ -0,0 +1,6 @@
+-- Cannot add or drop partition columns with CREATE OR REPLACE VIEW if partitions currently exist (must specify partition columns)
+
+drop view v;
+create view v partitioned on (ds, hr) as select * from srcpart;
+alter view v add partition (ds='1',hr='2');
+create or replace view v as select * from srcpart;

ql/src/test/queries/clientnegative/create_or_replace_view2.q

@@ -0,0 +1,6 @@
+-- Cannot add or drop partition columns with CREATE OR REPLACE VIEW if partitions currently exist
+
+drop view v;
+create view v partitioned on (ds, hr) as select * from srcpart;
+alter view v add partition (ds='1',hr='2');
+create or replace view v partitioned on (hr) as select * from srcpart;

ql/src/test/queries/clientnegative/create_or_replace_view3.q

@@ -0,0 +1,3 @@
+-- Existing table is not a view
+
+create or replace view src as select ds, hr from srcpart;

ql/src/test/queries/clientnegative/create_or_replace_view4.q

@@ -0,0 +1,5 @@
+-- View must have at least one non-partition column.
+
+drop view v;
+create view v partitioned on (ds, hr) as select * from srcpart;
+create or replace view v partitioned on (ds, hr) as select ds, hr from srcpart;

ql/src/test/queries/clientnegative/create_or_replace_view5.q

@@ -0,0 +1,5 @@
+-- Can't combine IF NOT EXISTS and OR REPLACE.
+
+drop view v;
+create view v partitioned on (ds, hr) as select * from srcpart;
+create or replace view if not exists v as select * from srcpart;

ql/src/test/queries/clientnegative/create_or_replace_view6.q

@@ -0,0 +1,5 @@
+-- Can't update view to have an invalid definition
+
+drop view v;
+create view v partitioned on (ds, hr) as select * from srcpart;
+create or replace view v partitioned on (ds, hr) as blah;

ql/src/test/queries/clientnegative/create_or_replace_view7.q

@@ -0,0 +1,7 @@
+-- Can't update view to have a view cycle (1)
+
+drop view v;
+create view v1 partitioned on (ds, hr) as select * from srcpart;
+create view v2 partitioned on (ds, hr) as select * from v1;
+create view v3 partitioned on (ds, hr) as select * from v2;
+create or replace view v1 partitioned on (ds, hr) as select * from v3;

ql/src/test/queries/clientnegative/create_or_replace_view8.q

@@ -0,0 +1,5 @@
+-- Can't update view to have a view cycle (2)
+
+drop view v;
+create view v1 partitioned on (ds, hr) as select * from srcpart;
+create or replace view v1 partitioned on (ds, hr) as select * from v1;

ql/src/test/queries/clientnegative/recursive_view.q

@@ -0,0 +1,15 @@
+-- Can't have recursive views
+
+drop table t;
+drop view r0;
+drop view r1;
+drop view r2;
+drop view r3;
+create table t (id int);
+create view r0 as select * from t;
+create view r1 as select * from r0;
+create view r2 as select * from r1;
+create view r3 as select * from r2;
+drop view r0;
+alter view r3 rename to r0;
+select * from r0;