[ 
https://issues.apache.org/jira/browse/TAJO-1493?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14900312#comment-14900312
 ] 

ASF GitHub Bot commented on TAJO-1493:
--------------------------------------

Github user jihoonson commented on a diff in the pull request:

    https://github.com/apache/tajo/pull/772#discussion_r39945793
  
    --- Diff: 
tajo-plan/src/main/java/org/apache/tajo/plan/expr/AlgebraicUtil.java ---
    @@ -493,4 +497,190 @@ public Object visitTimeLiteral(Object ctx, 
Stack<Expr> stack, TimeLiteral expr)
           return super.visitTimeLiteral(ctx, stack, expr);
         }
       }
    +
    +  /**
    +   * Find the top expr matched to type from the given expr
    +   *
    +   * @param expr start expr
    +   * @param type to find
    +   * @return a found expr
    +   */
    +  public static <T extends Expr> T findTopExpr(Expr expr, OpType type) 
throws TajoException {
    +    Preconditions.checkNotNull(expr);
    +    Preconditions.checkNotNull(type);
    +
    +    ExprFinder finder = new ExprFinder(type);
    +    finder.visit(null, new Stack<Expr>(), expr);
    +
    +    if (finder.getFoundExprs().size() == 0) {
    +      return null;
    +    }
    +    return (T) finder.getFoundExprs().get(0);
    +  }
    +
    +  private static class ExprFinder extends SimpleAlgebraVisitor<Object, 
Expr> {
    +    private List<Expr> list = new ArrayList<Expr>();
    +    private final OpType[] tofind;
    +    private boolean topmost = false;
    +    private boolean finished = false;
    +
    +    public ExprFinder(OpType... type) {
    +
    +      this.tofind = type;
    +    }
    +
    +    public ExprFinder(OpType[] type, boolean topmost) {
    +      this(type);
    +      this.topmost = topmost;
    +    }
    +
    +    @Override
    +    public Expr visit(Object ctx, Stack<Expr> stack, Expr expr) throws 
TajoException {
    +      if (!finished) {
    +        for (OpType type : tofind) {
    +          if (expr.getType() == type) {
    +            list.add(expr);
    +          }
    +          if (topmost && list.size() > 0) {
    +            finished = true;
    +          }
    +        }
    +      }
    +      return super.visit(ctx, stack, expr);
    +    }
    +
    +    public List<Expr> getFoundExprs() {
    +      return list;
    +    }
    +
    +  }
    +
    +  public static Expr[] toConjunctiveNormalFormArray(Expr expr) {
    --- End diff --
    
    Unnecessary change.


> Make partition pruning based on catalog informations
> ----------------------------------------------------
>
>                 Key: TAJO-1493
>                 URL: https://issues.apache.org/jira/browse/TAJO-1493
>             Project: Tajo
>          Issue Type: Sub-task
>          Components: Catalog, Planner/Optimizer
>            Reporter: Jaehwa Jung
>            Assignee: Jaehwa Jung
>             Fix For: 0.11.0, 0.12.0
>
>         Attachments: TAJO-1493.patch, TAJO-1493_2.patch, TAJO-1493_3.patch, 
> TAJO-1493_4.patch
>
>
> Currently, PartitionedTableRewriter take a look into partition directories 
> for rewriting filter conditions. It get all sub directories of table path 
> because catalog doesn’t provide partition directories. But if there are lots 
> of sub directories on HDFS, such as, more than 10,000 directories, it might 
> be cause overload to NameNode. Thus, CatalogStore need to provide partition 
> directories for specified filter conditions. I designed new method to 
> CatalogStore as follows:
> * method name: getPartitionsWithConditionFilters
> * first parameter: database name
> * second parameter: table name
> * third parameter: where clause (included target column name and partition 
> value)
> * return values: 
> List<org.apache.tajo.catalog.proto.CatalogProtos.TablePartitionProto>
> * description: It scan right partition directories on CatalogStore with where 
> caluse. 
>   For examples, users set parameters as following:
> ** first parameter: default
> ** second parameter: table1
> ** third parameter: COLUMN_NAME = 'col1' AND PARTITION_VALUE = '3
> In the previous cases, this method will create select clause as follows.
> {code:xml}
> SELECT DISTINCT A.PATH
> FROM PARTITIONS A, (
>   SELECT B.PARTITION_ID
>   FROM PARTITION_KEYS B
>   WHERE B.PARTITION_ID > 0 
>   AND (
>     COLUMN_NAME = 'col1' AND PARTITION_VALUE = '3'
>   )
> ) B
> WHERE A.PARTITION_ID > 0
> AND A.TID = ${table_id}
> AND A.PARTITION_ID = B.PARTITION_ID
> {code}
> At the first time, I considered to use EvalNode instead of where clause. But 
> I can’t use it because of recursive related problems between tajo-catalog 
> module and tajo-plan module. So, I’ll implement utility class to convert 
> EvalNode to SQL.



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