The end result is that programs may read the file in arrival sequence. As400 logical files compared to create view ibm db2. I was creating ibm i as400 based files that a webbased application would use. It allows your iseries applications, 5250 terminals, pc mail clients, or any browser to exchange internet. Loosely translated, what current users, jobseekers, and organizations want to know is whether a platform that was introduced in 1988 is still relevant today. How to correctly use pfile keyword in dds logical file. Descend descend keyword for physical and logical files. I was creating ibm ias400 based files that a webbased. A logical file can contain up to 32 record formats. Override the member to the member you want to retrieve. What is a physical and logical file in the as400 database.
One way is to use the copy file cpyf to copy the logical file to a new physical file. Workload performance series as400 software is a comprehensive, integrated suite of modules for your ibm i iseries, as400, system i servers that looks at virtually every aspect of your systems application processing environment to diagnose and eliminate processing bottlenecks while avoiding unnecessary hardware upgrades. Now we know its based on multiple physical files and that you dont want just a copy of the logical file. Customer information file customer number 5 digit numeric field. Selectomit fields in dds for physical and logical files. Logicals can be used for updating, creating and deleting data within the physical that it is scoped over.
For join logical files, the selectomit field name you specify must be specified at the field level in positions 19 through 28. Does anyone know how to determine what the key fields are for a logical file on an as400 from a query. One or more logical file can be derived from a single physical file. Jan 23, 20 it looks like john wants to retrieve the record with the highest effective date within a subset of records in the file limited to whatever the value of the insco field is.
All fields must be listed in the logical file s dds. In v5r2, when there were only the physical file and an index, the query optimzer would use the index to perform the query. I want to build some test libraries from my production libraries. Difference between physical file and logical file in as400 is. Descend keyword for physical and logical files ibm knowledge. Jun 27, 2012 does anyone know how to determine what the key fields are for a logical file on an as400 from a query. Jan 29, 2014 but that api does not permit sorting by object size. Keyword entries are typed in positions 45 through 80 functions. Basically an identity column is a column in a table that is updated by db2 with the next sequential value. Creating physical and logical files in as400 the as400 database, db2400 is part of the as400 operating system. Is it possible to create logical files with sql statements. How we can delete all the logical file of a physical file in one instance. The system automatically starts journaling logical files built over a journaled physical file when it finds a need to. When i check the results, the information presented is not sorted at all and it shows the contents of the regular physical.
Go to the 3 various department menus run the cif query program access the spool file sign off. Physical and logical files this book provides the reference information you need to know for coding the data description specifications dds for physical and logical. The cif master file must only exist in one place, but all departments must be able to access the same file. Any access path associated with the logical file is not covertly journaled. Keyesmail is a full function automated email package for the ibm i i5, iseries, as400. Dynamic select occurs whenever the program reads file.
Most of the time, a logical file is nothing more than a way of accessing the physical file with different key fields. I can also substring a field from the physical file into fields in the logical. For join logical files, the selectomit field name you. The users disliked that way that the fields in the webbased application were sorted, which was in ebcdic, and wanted it in ascii order. Meanwhile, the data in the physical file records is scattered all over the asp. With the standard as400 supplied tools, it is hard to see the logical file. For some purposes, i use a view which is defeined something like this.
Jan 22, 2014 when you perform an output operation to the logical file the first 3 characters are written to the physical files field, and the fourth character is lost. A new logical file has been added to the system to allow sorting of the mail by member name. It is a relational database and has features similar to other databases you. Nick litten dot com is a mixture of blog posts that can be sometimes serious, frequently playful and probably downright pointless all in the space of a day. This is the full source code for the subfile sort program that appeared in the may 2004 issue of the iseries extra newsletter. Anyone who has been around the iseries for a while knows what a lifesaver the retrieve cl source rtvclsrc command can be. How to find keys in as400 logical file with sql solutions. You can do this either by sorting the file or reorganizing it into the sequence in which it is most often processed and then processing the file sequentially. What is the select and omit criteria in as400 logical. The first 2 characters are the sales territory for which there are numerous combinations. Keyesmail automated email for the ibm i computer keyes. Dec 06, 20 it is actually a list of pointers to the physical file. The parameter name on the sst keyword is not valid as a selectomit field unless it is defined elsewhere in the logical file record format.
The cif master file must only exist in one place, but all departments must be able to. The logical file system manages open file table entries and perprocess file descriptors. A logical file is a database file that describes how data records contained in one or more physical files are presented to a program. Logical file and types of logical file, single and multiple record format nonjoin logical file, levels of. I have a file with a 15 lenght alphanumerick key field. A logical file is a type of database file that points to one or more physical files. Ibm as400 interview questions and answers all india exams. Keyword entries for physical and logical files positions. Physical and logical files this book provides the reference information you need to know for coding the data description specifications dds for physical and logical files that can be described externally. Feu offers fullscreen multiplerecord displays, custom savable views of the database, custom selection capabilities, database relations, a pdm interface and many specialized functions that will save a lot of time. Sorting within a program rpg report program generator tektips. Home interview technical interview questions and answers software tools ibm tools as400 discussion. But that api does not permit sorting by object size.
What is the difference between a logical file crtlf and index create index. Logical files can be derived from 1 to 32 physical files and so a logical file can have a maximum of 32 record formats. Select a specific version or edition of ibm i documentation. Change all programs that use the physical file to use the new logical file instead and recompile them. Each record your program reads will return the same format, called. Retrieve dds source for a physical or logical file cl.
What is the select and omit criteria in as400 logical files. The create logical file crtlf command creates a logical file from the information specified on this command and from the data description specifications dds contained in a source file. I am having trouble duplicating logical files that are. With a rpg ile program compiled with no special options, the alternate collating sequence. The sort sequence table defined for the job and used by the program should. That restriction forces us to use record format names imrec and ibrec in the multiformat logical file. If the logical file has selectomit criteria, put the criteria in. Ibm i as400, iseries application performance tuning software. If a physical file has key fields, programs can randomly access the records or read them. In v5r2, when there were only the physical file and an index, the query optimzer would use the index to. Multiformat logical files ibm i5iseries primerc concepts.
A view is not an index, though, and you cant mix an index and a view like you can with a keyed logical with selectomits. But if a logical files underlying physical file is journaled and the logical file contains access paths built over that physical file, then you can use the start journal access paths strjrnap. More than alternate sort sequences details ted holt. Performance analysis of these jobs usually reveals a ratio of one physical read for every logical read i. Youll need to determine if crystal reports can send a command before. Since then the as400 has had several name changes such as iseries, system i. Absval absolute value keyword for physical and logical files you can use this keyfield level keyword to direct the. Selecting and omitting records for ibm i logical files. The result is journal entries recording things like authority changes for logical files. How we can delete all the logical file of a physical file. It simply contains the record selection definition and when accessed retrieves the records from the physical file to which it refers. It is a relational database and has features similar to other databases you may have used such as microsoft access, oracle or dbase. We dont need it as a sort field, so we will just attach it as an additional field.
Im running os400 v3r1 today but will in 14 days upgrade to v3r7. Also, if there is a more modern way to do this, i would be happy to learn. Here is the join logical spec but it is not compiling. Nonjoin logical files can either be a simple logical file, which contains only one record format or a multiple record format logical file, which contains more than one record format. You can either create a joined logical file which will join file1 and file2, replacing file3 in your program, and dispense with the overrides. This should allow you to find a specific message, such as a template, much easier.
Feu file edit utility db2 database tool and file editor. And finally what i think is the weirdest thing i have had to do with a logical file field. But if a logical file s underlying physical file is journaled and the logical file contains access paths built over that physical file, then you can use the start journal access paths strjrnap command to start journaling the logical file. I could change the sort order by using the trntabl, translation table, function. I am linking from ms access with vba and i need to specify the keys in order to update. It looks like john wants to retrieve the record with the highest effective date within a subset of records in the file limited. Nick litten dot com is a mixture of blog posts that. The record formats in the multiformat logical must have the same names as they do in the physical file from which they come. Set up the clp programs on the menus you have created. The system38 evolved into the as400 in 1988 and s of applications have been developed for the as400 in areas such as banking, insurance, manufacturing and retail. It is actually a list of pointers to the physical file. Files accessed by logical file pfile file library lf format.
I could use a logic view, but i dont do dds and dont want to ship dds. I made a test generating a report from a logical file and the same from a physical file and the result was different. Charles wilt iseries systems administrator developer mitsubishi electric automotive america ph. Charles wilt iseries systems administrator developer mitsubishi electric. I am linking from ms access with vba and i need to specify the keys. For a zip file containing all the sources, click here. Ibm as400 interview questions and answers discussion. The record formats in the multiformat logical must have the same names as they do in the physical file from which they. Jan 16, 2008 the reorganize physical file rgzpfm commands keyfile parameter provides a way to physically order records in the file. As400 logical files how to see inside solutions experts.
Categories software mainframe ibm as400 ibm as400 allother. If you need to create a logical file selectomit criteria, then you need to create a view. I wondered if i used qsql to build an index over the outfile, if i could then process that index as a database file in cl. Sql statement slower on as400 console than from remote odbc closed ask question. Lf with date key in descending order midrange news. A logical file does not contain any data but provides the views of the data to satisfy endusers needs. Logical record is the information used by the program. Feu offers fullscreen multiplerecord displays, custom savable views of the database, custom selection capabilities, database relations, a pdm interface and many. In computing, a file system or filesystem often abbreviated to fs, controls how data is stored. You can use this key fieldlevel keyword to specify that the values of this character, hexadecimal, or numeric key field are retrieved in descending sequence. That is, this logical file must have an identical record format and the same key. It was unusual in that the file management program macintosh finder created the illusion of a partially hierarchical filing system on top of. The source for the display file and the product file used in the example follow the rpg source.
I am having trouble duplicating logical files that are stored in one library but point to physical files in another library. In my opinion identity columns are one of the cool things in db2 for i. The solution which is closest to your join logical file is a join logical view. If thats the case, using start would not work since it would position you to the beginning of the file, and you want to be at the beginning of the group equal to the value. Difference between physical file and logical file in as400. If you are viewing a logical file, instead of the file size, you will see lf indicating this is a logical file which is not the actual size of the data. If you specify keyfilefile, the data will be stored in key sequence. The logical file is a sequenced view of the data in the physical file. Join logicals are an advanced form of logical file selecting and sequencing data from more than one physical.
Ibm i software developer, digital dad, as400 anarchist, rpg modernizer, alpha nerd and passionate eater of cheese and biscuits. For simple and multipleformat logical files, the operating system uses the following search order to match selectomit field names with defined fields. Fields specified in dds positions 19 through 28 fields specified as parameters on the concat or rename keyword if the field name is specified more than once. If you wish to query a logical file from an sql statement, consider querying the underlying physical files instead. Logical file custma02 provides access to the email address field and. These days, logical files and sql are the iseries methods of choice for.
Programmer productivity tools and system utility software for the iseries and system i applied logic offers a catalog of powerful programmer productivity tools and system utilities. Programmer productivity tools and system utility software. Selecting and omitting logical file records using the open query file opnqryf command as an alternative to using dds, you can select and omit records for a logical file by specifying the qryslt parameter on the open query file opnqryf command. You may also specify the name of a logical file if you wish to store the data in the order of the logical files key fields. Dds for physical and logical files this book provides the reference information you need to know for coding the data description specifications dds for physical and logical files that can be.
Creating physical and logical files in as400 friends400. If a cl source member is accidentally deleted or if youd like to examine a cl program for which you never had source, the rtvclsrc command will recreate a program source member for you from a cl program object provided that the original programmer lets his cl source be. It simply contains the record selection definition and when. See signed signed keyword for physical and logical files for an example of data sorted using the descend keyword. In cobol programs, only one record can be handled at any point of time and it is called as logical record.
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