xasl_analytic.hpp

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/*
 * Copyright 2008 Search Solution Corporation
 * Copyright 2016 CUBRID Corporation
 *
 *  Licensed under the Apache License, Version 2.0 (the "License");
 *  you may not use this file except in compliance with the License.
 *  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 *
 */

//
// xasl_analytic - defines XASL structures for analytics
//

#ifndef _XASL_ANALYTIC_HPP_
#define _XASL_ANALYTIC_HPP_

#include "dbtype_def.h"
#include "regu_var.hpp"             // regu_variable_node
#include "storage_common.h"       // FUNC_TYPE, QUERY_OPTIONS

// forward definitions
struct qfile_list_id;
struct sort_list;
typedef struct sort_list SORT_LIST;   // todo - rename sort_list member.
struct tp_domain;

namespace cubxasl
{
  struct analytic_ntile_function_info
  {
    bool is_null;           /* is function result NULL? */
    int bucket_count;       /* number of required buckets */
  };

  struct analytic_cume_percent_function_info
  {
    int last_pos;           /* record the current position of the rows that are no larger than the current row */
    double last_res;        /* record the last result */
  };

  struct analytic_percentile_function_info
  {
    double cur_group_percentile;    /* current percentile value */
    regu_variable_node *percentile_reguvar; /* percentile value of the new tuple if this is not the same as
                                                 * cur_gourp_percentile, an error is raised. */
  };

  union analytic_function_info
  {
    analytic_ntile_function_info ntile;
    analytic_percentile_function_info percentile;
    analytic_cume_percent_function_info cume_percent;
  };

  struct analytic_list_node
  {
    analytic_list_node *next;       /* next analytic node */

    /* constant fields, XASL serialized */
    FUNC_TYPE function;     /* analytic function type */
    QUERY_OPTIONS option;       /* DISTINCT/ALL option */
    tp_domain *domain;      /* domain of the result */
    tp_domain *original_domain; /* domain of the result */

    DB_TYPE opr_dbtype;     /* operand data type */
    DB_TYPE original_opr_dbtype;    /* original operand data type */
    regu_variable_node operand; /* operand */

    int flag;           /* flags */
    int sort_prefix_size;       /* number of PARTITION BY cols in sort list */
    int sort_list_size;     /* the total size of the sort list */
    int offset_idx;     /* index of offset value in select list (for LEAD/LAG/NTH_value functions) */
    int default_idx;        /* index of default value in select list (for LEAD/LAG functions) */
    bool from_last;     /* begin at the last or first row */
    bool ignore_nulls;      /* ignore or respect NULL values */
    bool is_const_operand;  /* is the operand a constant or a host var for MEDIAN function */

    /* runtime values */
    analytic_function_info info;    /* custom function runtime values */
    qfile_list_id *list_id; /* used for distinct handling */
    db_value *value;        /* value of the aggregate */
    db_value *value2;       /* for STTDEV and VARIANCE */
    db_value *out_value;        /* DB_VALUE used for output */
    db_value part_value;        /* partition temporary accumulator */
    int curr_cnt;           /* current number of items */
    bool is_first_exec_time;    /* the fist time to be executed */

    void init ();
  };

  struct analytic_eval_type
  {
    analytic_eval_type *next;   /* next eval group */
    analytic_list_node *head;       /* analytic type list */
    SORT_LIST *sort_list;       /* partition sort */

    analytic_eval_type () = default;
  };
} // namespace cubxasl

using ANALYTIC_NTILE_FUNCTION_INFO = cubxasl::analytic_ntile_function_info;
using ANALYTIC_CUME_PERCENT_FUNCTION_INFO = cubxasl::analytic_cume_percent_function_info;
using ANALYTIC_PERCENTILE_FUNCTION_INFO = cubxasl::analytic_percentile_function_info;
using ANALYTIC_FUNCTION_INFO = cubxasl::analytic_function_info;
using ANALYTIC_TYPE = cubxasl::analytic_list_node;
using ANALYTIC_EVAL_TYPE = cubxasl::analytic_eval_type;

#endif // _XASL_ANALYTIC_HPP_