Visual Explain (QQQVEXPL) API

Required Parameter Group:

1	Pointer to qualified query name	Input	CHAR(*)
2	Pointer to qualified database monitor table	Input	CHAR(*)
3	Pointer to the set of records returned	I/O	PTR(SPP)
4	Pointer to the return code structure	I/O	CHAR(*)

Threadsafe: Conditional; see Usage Notes.

The Visual Explain (QQQVEXPL) API is used to create a query graph that graphically displays the execution of an SQL statement. You can use this tool to see information about both static and dynamic SQL statements. QQQVEXPL supports the following types of SQL statements:

Select
Insert
Update
Delete

You can use this tool to better understand where the highest costs of your queries are taking place. You can improve query performance by:

Rewriting your SQL statement.
Changing query attributes and environment settings.
Creating any recommended indexes.

You also can use the QQQVEXPL API to:

View the statistics that were used at the time of optimization.
Determine whether an index was used to access a table. If an index was not used, Visual Explain can help you determine which columns might benefit from being indexed.
View the effects of performing various tuning techniques by comparing the before and after versions of the query graph.
Obtain information about each operation in the query graph, including the total estimated cost and number of rows retrieved.

Input to the Visual Explain (QQQVEXPL) API is two structures. One contains the information the Visual Explain consolidator needs to uniquely identify which query within the database monitor table is to be explained. The other contains the name of the database monitor table. The database monitor table is a table that contains the records resulting from an execution of the STRDBMON command. Output from the Visual Explain (QQQVEXPL) API is a pointer to a stream of data located in user domain storage. This data contains the information necessary to create a pictorial view of how the specified query was implemented. It is up to the user to clean up the user domain storage. Also, output is a structure that contains an error return code, the number of entries in the output data, and the entry number of the Final Select ICON. To create the picture, the user starts with the entry of the Final Select ICON and works back to the beginning ICONs.

The format for the output records (or array entries) can be found in Output Format. Each record has a unique I CON number associated with it. The unique ICON number associates the records to a particular ICON. That is, all records with the same unique ICON number are associated with one specific ICON. For example, if the Final Select ICON has a unique ICON number of 12, then all records with a unique ICON number of 12 contain information about the Final Select ICON. The record immediately following the Final Select record is the record that tells the user how many ICONs (called child ICONs) are branched off the Final Select ICON. This record will have a record type of 11, which means it contains the number of child ICONs. The unique ICON number will match the unique ICON number of the Final Select ICON. Therefore, we know this record is telling us how many child ICONs there are for the Final Select ICON. The next records will contain the ICON number of the child ICONs. There will be one record for each child ICON and they will have a record type of 12 (unique ICON number of the child ICON). The user can find the record that corresponds to the child ICON by searching for the record that has a record type of 10 (new ICON) and a unique ICON number that matches the ICON number of the child ICON. Once the record of the child ICON is found, the process starts over again. All the records associated with that ICON (that is, that have the same unique ICON number) are read and processed. Any child ICONs are put on a stack or queue to be processed next. To see the list of possible record types, see Record Types.

The heart of the picture that is generated is the ICONs. In general, each ICON represents an operation performed during the execution of the query. It is up to the user to create and design the ICONs to be used. The connection between the output data and the user's ICONs is the label of the ICON that is returned within the new ICON record (record type of 10). The user is expected to match the non-translated label that is returned to the label that corresponds to the specific ICON. The non-translated ICON label is returned in the character output field. The translated ICON label is returned in the column heading field. For a list of ICON labels, see ICON Labels. For a detailed description of the operation represented by each ICON, see Database Performance and Query Optimization in the iSeries Information Center.

Authorities and Locks

Library Authority: *EXECUTE
Table Authority: *OBJOPR, *READ

Required Parameter Group

Pointer to the qualified query

INPUT; CHAR(*)

A pointer to a variable length structure that is used to determine the query to be explained. The structure contains two variables:

Type	Description
BINARY(2)	Length of the structure that contains the qualified query.
CHAR(*)	Structure used to determine the specific query to be explained. This structure contains seven variables. Generally, these variables are set to the same value as the corrsponding variables in the QQJFLD field within the QQQ1000 record of the query to be explained. One way to find the appropriate QQQ1000 record within the database monitor table is to view the SQL statement text (field QQ1000) and compare it to the SQL statement text of the query you wish to have explained. System name CHAR(8). A specific iSeries name. It is set to the same value as the QQSYS field or the first 8 bytes of field QQJFLD. Job name CHAR(10). A specific job name. It is set to the same value as the QQJOB field or bytes 9 to 18 of field QQJFLD. Job user CHAR(10). A specific user profile name. It is set to the same value as the QQUSER field or bytes 19 to 28 of field QQJFLD. Job number CHAR(6). A specific job number. It is set to the same value as the QQJNUM field or bytes 29 to 34 of field QQJFLD. Unique query count BINARY(4). A unique query number. It is set to the same value as found in bytes 35 to 38 of field QQJFLD (that is, Select hex(substr(QQJFLD,35,4)) From Montable). Statement number BINARY(4). A specific statement number. It is set to the same value as found in bytes 39 to 42 of field QQJFLD (that is, Select hex(substr(QQJFLD,39,4)) From Montable). Query Definition Template (QDT) number BINARY(4). A specific QDT number. It is set to the same value as found in bytes 43 to 46 of field QQJFLD (that is, Select hex(substr(QQJFLD,43,4)) From Montable).

Type

Description

BINARY(2)

Length of the structure that contains the qualified query.

CHAR(*)

Structure used to determine the specific query to be explained. This structure contains seven variables. Generally, these variables are set to the same value as the corrsponding variables in the QQJFLD field within the QQQ1000 record of the query to be explained. One way to find the appropriate QQQ1000 record within the database monitor table is to view the SQL statement text (field QQ1000) and compare it to the SQL statement text of the query you wish to have explained.

System name: CHAR(8). A specific iSeries name. It is set to the same value as the QQSYS field or the first 8 bytes of field QQJFLD.
Job name: CHAR(10). A specific job name. It is set to the same value as the QQJOB field or bytes 9 to 18 of field QQJFLD.
Job user: CHAR(10). A specific user profile name. It is set to the same value as the QQUSER field or bytes 19 to 28 of field QQJFLD.
Job number: CHAR(6). A specific job number. It is set to the same value as the QQJNUM field or bytes 29 to 34 of field QQJFLD.
Unique query count: BINARY(4). A unique query number. It is set to the same value as found in bytes 35 to 38 of field QQJFLD (that is, Select hex(substr(QQJFLD,35,4)) From Montable).
Statement number: BINARY(4). A specific statement number. It is set to the same value as found in bytes 39 to 42 of field QQJFLD (that is, Select hex(substr(QQJFLD,39,4)) From Montable).
Query Definition Template (QDT) number: BINARY(4). A specific QDT number. It is set to the same value as found in bytes 43 to 46 of field QQJFLD (that is, Select hex(substr(QQJFLD,43,4)) From Montable).

Pointer to qualified monitor table

INPUT; CHAR(*)

A pointer to a CHAR(72) structure containing the name of the database monitor table and other optional variables. The structure contains nine variables:

Type	Variable	Description
CHAR(10)	Monitor table name	Name of the database monitor table that contains the query to be explained.
CHAR(10)	Monitor library name	Library of the database monitor table.
CHAR(3)	Date format	A specific date format or blanks. I f blank, the date format of the current job will be extracted and used. Possible date formats are: USA ISO EUR JIS MDY DMY YMD JUL
CHAR(1)	Date separator	A specific date separator or J. If J, the date separator of the current job will be extracted and used. Possible date separators are: "/" "-" "." "," " "
CHAR(3)	Time format	A specific time format. It must be one of the following values: USA ISO EUR JIS HMS
CHAR(1)	Time separator	A specific time separator or J. If J, the time separator of the current job will be extracted and used. Possible time separators are: ":" "." "," " "
CHAR(1)	Decimal point	A specific decimal point, J, or blank. If J or blank, the decimal point of the current job will be extracted and used. Possible decimal points are: "." ","
CHAR(3)	Language ID	A specific language ID, J, or blanks. If J or blanks, the language ID of the current job will be extracted and used. Currently, the language ID is not used and it is recommended this value be set to blanks.
CHAR(40)	Reserved	Open for future expansion. These should be set to hexadecimal zeros.

Pointer to output data

I/O; PTR(SPP)

A pointer to data that can be viewed as a set of records or multiple entries within an array. This data is used to determine the pictorial representation of the query. The user can retrieve the data in any manner. One suggested method is to view the returned data as a set of records and use the SET RESULTS SETS command within an SQL procedure to retrieve the output data. To see the format of the output data, see Output Format. Once finished, it is up to the user to deallocate or destroy the space containing the output data.

Pointer to output return code

I/O; CHAR(*)

Pointer to a CHAR(32) structure that contains the following output information:

Type	Variable	Description
BINARY(4)	Error code	Error code returned from the Visual Explain consolidator. See Error Codes for a list of possible return codes.
BINARY(4)	Number of records returned	Number of records (or array entries) returned.
BINARY(4)	Final select record	Record number (or array entry), within the set of records returned, of the Final Select ICON.
BINARY(4)	Reserved	Currently not used.
BINARY(4)	Reserved	Currently not used.
BINARY(4)	Reserved	Currently not used.
BINARY(4)	Reserved	Currently not used.
BINARY(4)	Reserved	Currently not used.

Usage Notes

This function is threadsafe, but not thread-enabled. Database monitor data is collected in the threaded process.

Output Format

The format for each record (or each array entry) in the output data is as follows:

Offset		Type	Field
Dec	Hex	Type	Field
0	0	BINARY(4)	Unique ICON number. Each icon in the picture is given a unique number. This value is what ties the records together; that is, all records with the same unique ICON number are associated with that specific ICON.
4	4	BINARY(4)	Record type or ID. Each record can be one of many possible types. See Record Types for the list of possible record types. A record type of 10 (new ICON) indicates another ICON was added to the picture and its unique number can be found in the unique ICON number field.
8	8	BINARY(4)	Context type. The type of context with which this record is associated. A context is a group of values used for a special purpose. See Context Types for the list of possible contexts.
12	C	BINARY(4)	Context order. If this record is associated with a context type, this is the order, or position, within the context for the value. For example, table name would have a context order of two since it is the second variable of information associated with the table description context. Table library would have a context order of one.
16	10	BINARY(4)	Flyover order. The order, or position, within the flyover information for this value. The flyover information is the information that is shown when the cursor is held over a particular ICON and a window pops up showing some of the data attributes associated with that ICON.
20	14	BINARY(4)	Arrow order. The order, or position, within the arrow information for this value. The arrow information is the information shown on the arrows that connect the ICONs.
24	18	BINARY(4)	Arrow value. The value shown on the arrow that connects the ICONs together. Generally, this value is either the estimated number of rows or the estimated processing time.
28	1C	BINARY(4)	Format value. Used to highlight or format output data. For example, all header lines within the data attributes will have a format value associated with them. This identifies all the header records and allows users the option to format these specific records in the same manner.
32	20	CHAR(1)	Specifies (yes or no) if the data attributes associated with the ICON are returned in a predetermined (numerical) order. This variable is set only for the record whose context type is new ICON. This variable is pertinent only to those users who wish to show the data attributes in the same order that the Visual Explain consolidator returned them. Users who wish to choose their own order of data attributes can simply ignore this indicator.
33	21	CHAR(1)	Type of output data. The type of output data is either "C", "N", or "X". It is the field that contains the character output ("C") or the field that contains the numeric output ("N"). It tells the user which field to look in for the output data. A value of "X" indicates the character output exceeds 1000 bytes and the remaining character output is found on the following array entry.
34	22	BINARY(2)	Length, in bytes, of the column heading.
36	24	CHAR(128)	Column heading. The description, or heading, of the output data. For a record type of new ICON, this will be the label of the ICON. For a data attribute record type, this will be a description of the data attribute; for example, Table name.
164	A4	BINARY(4)	Reserved.
168	A8	BINARY(4)	Reserved.
172	AC	BINARY(4)	Reserved.
176	B0	BINARY(2)	Length, in bytes, of the character output data. It is set only if the type of output is "C" or "X".
178	B2	CHAR(1000)	Character output. The character output could be many things, depending on the record type. For a new ICON record, the character output is the label associated with the ICON. For a data attribute, the character output is the value for that data attribute. For example, if the column heading was Table name, then the character output would be TABLE001. It is set only if the type of output is "C" or "X".
1178	49A	BINARY(4)	Numeric output. The numeric output is used only for a record that has a numeric output (that is, the child ICON record type or number of child ICONs record type). Generally, most records (especially data attribute records) have their output converted to character format. It is set only if the type of output is "N".
1182	49E	BINARY(2)	Reserved.

ICON Labels

To determine which ICON should be shown, look at the non-translated ICON label that is returned in the character output field. Compare this text string to the text string associated with the user-generated ICONs. The ICON labels that may be returned are shown below. For a detailed description of the operation represented by the ICON, refer to Database Performance and Query Optimization in the iSeries Information Center.

ICON Label	Description
Table Scan	All rows in the table were paged in and selection criteria was applied against each row. Only those rows meeting the selection criteria were retrieved. To get the result in a particular sequence, you must specify the ORDER BY clause.
Table Scan, Parallel	A table scan access method was used and multiple tasks were used to select the rows in parallel. The table was partitioned and each task was given a portion of the table with which to work.
Index Scan - Key Selection	All entries of the index were paged in. (This is different from key positioning, where only a specified range of key entries were paged in.) Any selection criteria, whose predicates match the key columns of the index, were applied against the index entries. Only selected key entries were used to select rows from the corresponding table data.
Index Scan - Key Selection, Parallel	Multiple tasks were used to perform key selection in parallel. The table was partitioned and each task was given a portion of the table with which to work.
Index Scan - Key Positioning
Index Scan - Key Positioning, Parallel	Multiple tasks were used to perform the key positioning in parallel. The range of key values was determined by the selection criteria whose predicates matched the key columns of the index. The number of selected key entries were further reduced by the use of index key selection or derived selection after key positioning was completed. Only selected key entries were used to select rows from the corresponding table data.
Skip Sequential Table Scan	A bitmap was used to determine which rows would be selected. No CPU processing was done on rows not selected and I/O was minimized by bringing in only those pages that contained rows to be selected.
Skip Sequential Table Scan, Parallel	A skip sequential table scan access method was used and multiple tasks were used to select the rows in parallel. The table was partitioned and each task was given a portion of the table with which to work.
Encoded Vector Index	Access was provided to a database file by assigning codes to distinct key values, and then representing these values in an array (vector). The elements of the array can be 1, 2, or 4 bytes in length, depending on the number of distinct values that must be represented. Because of their compact size and relative simplicity, encoded vector indexes provide for faster scans that can be more easily processed in parallel.
Encoded Vector Index, Parallel	Multiple tasks were used to perform the encoded vector index selection in parallel. T his allows for faster scans that can be more easily processed in parallel. The elements of the array can be 1, 2, or 4 bytes in length, depending on the number of distinct values that must be represented. Because of their compact size and relative simplicity, encoded vector indexes provide for faster scans and can be more easily processed in parallel.
Dynamic Bitmap	A bitmap was generated dynamically from an existing index. It then was used to determine which rows were to be retrieved from the table. To improve performance, dynamic bitmaps can be used in conjunction with any of the following access methods: Skip sequential table scan Index scan - key positioning Index scan - key selection
Temporary Table	A temporary table was required to contain the intermediate results of the query, or the queried table could not be queried as it currently exists and a temporary table was created to replace it.
Temporary Hash Table	A temporary hash table was created to perform hash processing.
Temporary Index	A temporary hash table was created to perform hash processing.
Hash Join	A temporary hash table was created to perform the join. T he tables queried were joined together using a hash join implementation where a hash table was created for each secondary table. Therefore, matching values were hashed to the same hash table entry.
Nested Loop Join	Queried tables were joined together using a nested loop join implementation. Values from the primary file were joined to the secondary file using an index whose key columns matched the specified join columns.
Index Grouping	Selected rows were grouped or summarized. Therefore, duplicate rows within a group were eliminated.
Hash Grouping	Selected rows were grouped or summarized. Therefore, duplicate rows within a group were eliminated.
Sort	Selected rows were sorted using a sort algorithm.
Union Merge	The results of multiple subselects were merged or combined into a single result.
Subquery Merge	The results of multiple subselects were merged or combined into a single result.
Bitmap Merge	Multiple bitmaps were merged or combined to form a final bitmap. The merging of the bitmaps simulates boolean logic (AND/OR selection).
Distinct	Duplicate rows in the result were prevented. You can specify that you do not want any duplicates by using the DISTINCT keyword, followed by the selected column names.
Select	A point in the query where multiple results are brought together into a single result set. For example, if a query is the union of two different select statements, at the point before the union occurs, the Select icon indicates the points where the select statements finished and the union is about to occur.
Final Select	The original text and summary information of how the query was implemented.
Insert	The original text and summary information of how the query was implemented.
Update	The original text and summary information of how the query was implemented.
Delete	The original text and summary information of how the query was implemented.
Unknown	The operation performed is not recognized by Visual Explain. For example, the system may support a new function that is not yet supported by Visual Explain.

Context Types

BINARY(4) A context is a group of values used for a special purpose.

Context	Type	Description
21	Table Description	The variables needed to retrieve information about the table. These variables are: Table library Table name
22	Index Description	The variables needed to retrieve information about the index. These variables are: Index library Index name
23	Create Index Attributes	The information needed to create an index. This includes: Library of base table Name of base table Type of index to create: "B" Binary radix index "E" Encoded vector index Number of unique values Key columns Alternate collating sequence library name Alternate collating sequence table name
24	Environment Attributes	Information about the environment when the query was executed. This includes: Memory pool size Memory pool ID Date format Date separator Time format Time separator Decimal point Sort sequence table name Sort sequence library name Language ID Query INI table name Query INI library name Query time limit Parallel degree Maximum number of tasks Parameter marker conversion

Format Types

BINARY(4) The formatting value is used to format or highlight similar output data. For example, all header lines within the data attribute output will have a format value associated with them. This allows the user the option to identify and format all these particular header lines in the same manner.

Format	Type	Description
8	Index Advised	Data attributes associated with the index advised function.
16	Header	Header line within the data attribute output.

Record Types

Generally, record types with a value less than 100 are used to construct the picture. For example, they determine which ICONs are connected together. Record types with a value greater than 1000 are data attributes (information associated with a particular ICON). For a detailed description of the data attributes, see Database Performance and Query Optimization in the iSeries Information Center.

Record Type	Description
10	New ICON.
11	Number of child ICONs.
12	Unique ICON number of the child ICON.
111	Heading only, no output data.
1010	Name of the index created.
1011	Library of the index created.
1012	Name of the temporary table created.
1013	Library of the temporary table created.
1014	Name of the temporary hash table created.
1015	Library of the temporary hash table created.
1031	Library of the table being queried.
1032	Name of the table being queried.
1033	Member name of the table being queried.
1034	Long name of the table being queried.
1035	Long library of the table being queried.
1041	Library of the base table.
1042	Name of the base table (underlying physical table).
1043	Member name of the base table.
1044	Long name of the base table.
1045	Long library of the base table.
1051	Library of the index used.
1052	Name of the index used.
1053	Member name of the index used.
1054	Long name of the index used.
1055	Long library of the index used.
1102	Time when the database monitor record was created.
1104	Timestamp of when the SQL statment started.
1106	Timestamp of when the SQL statement ended.
1108	Amount of time spent during optimization, in seconds.
1110	Amount of time spent creating the cursor (open data path), in seconds.
1112	Total time for the SQL statement, in milliseconds.
1114	Total time for the SQL statement, in microseconds.
1120	Statement OPEN time, in milliseconds.
1122	Statement FETCH time, in milliseconds.
1124	Statement CLOSE time, in milliseconds.
1220	Statement number.
1222	Statement function.
1224	Statement operation.
1226	Statement type.
1228	Statement name.
1230	Statement outcome.
1232	SQL return code.
1234	SQLSTATE.
1240	Cursor name.
1242	Package name.
1244	Package library.
1250	Number of rows returned.
1252	Number of rows fetched.
1260	SQL statement text.
1306	CLOSQLCSR value.
1308	ALWCPYDTA value.
1310	Pseudo open.
1312	Pseudo close.
1313	Hard close reason code.
1314	Open data path implementation.
1320	Dynamic replan reason code.
1324	Dynamic replan reason subcode.
1326	Timestamp of the last replan.
1330	Parse required.
1332	Data conversion.
1334	Level of commitment control.
1336	Blocking enabled.
1338	Delay preperation.
1339	Statement is explainable.
1340	Type of naming convention.
1342	Type of dynamic execution.
1344	Optimize LOB.
1350	User profile, static.
1352	User profile, dynamic.
1354	Default collection.
1360	Procedure name on the call.
1362	Procedure library on the call.
1364	Directory path.
2012	Estimated processing time, in seconds.
2016	Cumulative processing time, in seconds.
2018	Total number of rows in the table.
2020	Size of the table.
2042	Estimated number of rows selected.
2044	Estimated number of joined rows.
2046	Join position.
2048	Original file position.
2050	Join method.
2052	Join type.
2054	Join operator.
2056	Join fanout.
2058	Number of files joined.
2070	I/O or CPU bound.
2080	Reason code.
2110	Index scan, key positioning.
2112	Number of key columns for key positioning.
2114	Estimated number of entries selected through key positioning.
2116	Index scan, key selection.
2118	Estimated number of entries selected through key selection.
2122	Index only access.
2124	Index fits into main memory.
2126	Memory pool size.
2128	Memory pool ID.
2130	Skip key processing.
2140	Type of index.
2141	Index usage.
2142	Number of entries in the index.
2144	Number of unique values in the index.
2146	Percent overflow for the index.
2148	Vector size of the index.
2150	Size of the index used.
2152	Page size of the index used.
2154	Reason code of why index was used.
2160	Index is a constraint.
2162	Name of the constraint.
2182	Data space selection exists.
2184	Skip sequential processing was used.
2190	Reason code for the table scan processing.
2220	Index is a constraint.
2222	Name of the constraint.
2224	Data space selection exists.
2226	Skip sequential processing was used.
2320	The query optimizer timed out.
2322	Reason code of why the index was not used.
2324	List of indexes which the query optimizer considered.
2346	The query optimizer is advising an index to be created.
2348	The number of key columns within the index advised that will use key positioning.
2350	The list of key columns for the index advised.
2380	Was parallel pre-fetch used.
2382	Was parallel pre-load used.
2384	Parallel degree requested by the query optimizer.
2386	Parallel degree used.
2388	Reason code why the parallel degree requested by the optimizer was not used.
2402	Number of entries in the temporary index created.
2404	Page size of the temporary index created.
2406	Row size of the temporary index created.
2408	Was an alternate collating sequence table used to create the temporary index.
2409	Name of the alternate collating sequence table used to create the temporary index.
2410	Library of the alternate collating sequence table used to create the temporary index.
2412	Is the temporary index that was created reusable.
2414	Is the temporary index that was created a sparse or select/omit index.
2416	Type of index that was created.
2418	Was the index created as a permanent object.
2420	Was the index created from another index.
2422	Parallel degree requested by query optimizer for creation of the index.
2424	Parallel degree used during creation of the index.
2426	Reason code why the parallel degree requested by the optimizer for the index creation was not used.
2428	Reason code why a temporary index was created.
2430	Key columns used when creating the temporary index.
2510	Number of rows within the temporary table.
2512	Size of the temporary table.
2514	Row size of the temporary table.
2516	Default values exist in temporary table.
2518	Temporary table created is a temporary result table.
2520	Temporary table created is a distributed table.
2522	Nodes where the temporary distributed table was created.
2524	Reason code why a temporary table was created.
2550	Number of rows within the temporary hash table.
2552	Size of the temporary hash table.
2554	Row size of the temporary hash table.
2556	Key size of the temporary hash table.
2558	Element size of the temporary hash table.
2560	Memory pool size where temporary hash table was created.
2562	Memory pool ID where temporary hash table was created.
2563	Reason code why a temporary hash table was created.
2564	Columns used when creating the temporary hash table.
2612	Columns used for dataspace selection.
2614	Was derived selection used.
2616	Columns used for derived selection.
2620	Columns used for key positioning.
2622	Columns used for key selection.
2624	Columns used for join selection.
2626	Columns used for ordering.
2628	Columns used for grouping.
2810	Type of grouping implementation.
2812	Does HAVING selection exist.
2814	Was the HAVING selection converted into WHERE seletion.
2816	Estimated number of groups.
2818	Average number of rows within each group.
2820	Grouping columns.
2822	MIN columns.
2824	MAX columns.
2826	SUM columns.
2828	COUNT columns.
2830	AVERAGE columns.
2910	Subselect number of the inner subselect.
2912	Nested level of the inner subselect.
2914	Subselect number of the materialized view containing the inner subselect.
2916	Nested level of the materialized view containing the inner subselect.
2920	Subquery operator.
2922	Correlated columns exist.
2924	List of the correlated columns.
3020	Size of the bitmap created.
3022	Number of bitmaps created.
3024	IDs of the bitmaps created.
3026	IDs of the bitmaps that were merged together.
4020	System name.
4022	Job name.
4024	Job user.
4026	Job number.
4028	Unique query count.
4032	Subselect count.
4040	Relational database name.
4042	Thread ID.
4044	Unique refresh count.
4046	Subselect nested level.
4048	Materialization number of the subselect.
4050	Nested level of the subselect that was materialized.
4052	Materialization number for the decomposed subselect.
7008	List of the host variable values.
7009	Type of host variable implementation.
7010	Type of processing for the specified ordering.
7011	Name of the index used to satisfy ordering.
7012	Library of the index used to satisfy ordering.
7013	Long name of the index used to satisfy ordering.
7014	Long library of the index used to satisfy ordering.
7020	Type of processing for the specified grouping.
7021	Name of the index used to satisfy grouping.
7022	Library of the index used to satisfy grouping.
7023	Long name of the index used to satisfy grouping.
7024	Long library of the index used to satisfy grouping.
7026	Query contains UNION.
7027	Query contains subquery (subselect).
7030	Type of join processing.
7032	Query contains distinct.
7034	Query contains distributed tables.
7036	List of the nodes containing the distributed tables.
7050	Quick summary of the implementation.
8014	Memory pool size.
8016	Memory pool ID.
8020	Date format.
8022	Date separator.
8024	Time format.
8026	Time separator.
8028	Decimal point.
8030	Name of the sort sequence table associated with the query.
8032	Library of the sort sequence table associated with the query.
8034	Language ID.
8036	Country or region ID.
8040	Query INI table name.
8042	Query INI library.
8044	Maximum query time limit.
8046	Parallel options.
8048	Maximum number of tasks.
8050	Apply CHGQRYA options to remote systems.
8052	Asynchronous job usage.
8054	Join order was forced.
8056	Print debug messages.
8060	Parameter marker conversion.
8062	User defined function (UDF) time limit.
8064	Optimizer limitations.

Error Codes

Possible error codes returned from the Visual Explain consolidator are:

Error Code	Description
0	Successful.
71	Invalid date format.
72	Invalid date separator.
73	Invalid time format.
74	Invalid time separator.
75	Invalid decimal point.
90	No records in the specified database monitor table.
91	Failure trying to read records from specified database monitor table.
92	Query too complex to be explained.
93	Specified database monitor table not found.
99	Query function not supported.
1000	Missing or invalid QQQ1000 record within the database monitor table.
3000	Missing or invalid QQQ3000 record within the database monitor table.
3001	Missing or invalid QQQ3001 record within the database monitor table.
3002	Missing or invalid QQQ3002 record within the database monitor table.
3003	Missing or invalid QQQ3003 record within the database monitor table.
3004	Missing or invalid QQQ3004 record within the database monitor table.
3014	Missing or invalid QQQ3014 record within the database monitor table.
3021	Missing or invalid QQQ3021 record within the database monitor table.
3022	Missing or invalid QQQ3022 record within the database monitor table.
3023	Missing or invalid QQQ3023 record within the database monitor table.
3025	Missing or invalid QQQ3025 record within the database monitor table.
3027	Missing or invalid QQQ3027 record within the database monitor table.
3028	Missing or invalid QQQ3028 record within the database monitor table.
0nnn	SQL error code (converted to a positive value) that occurred while reading records from the specified database monitor table.

API introduced: V5R1

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