Copyright: Copyright © 1982-2001 Pervasive Software Inc. All Rights Reserved.


_ Keys
# Keys

This control indicates the number of different key specifications are currently defined in the File Information Editor.


Contents

The following Help Topics are available:

ACS Information

Browse

Copy

Create File

Create Index

Description File Comments

Drop Index

File Information Editor

File Specification Controls

Getting Help

Help on Help

Key Group box Help

Key Lists Help

Key Specification Controls Help

Key - Segment Group box Help

Load Data

About Btrieve Maintenance Utility

Miscellaneous File Information Help

Owner Name

Data Processing

Roll Forward Stat

Roll Forward

Save Data

Set - Clear Owner

Create Stat Report

View Stat Report


_ Pages
# Pages

This control specifies how many pages Btrieve preallocates when creating a new file.


_ Segments
# Segments

This control indicates the number of different key segment specifications are currently defined in the File Information Editor.


_ Free Space
% Free Space

This control specifies the percentage of space you want the MicroKernel to reserve on each variable page to allow for future expansion variable records. This allows you to reduce the amount of fragmentation of variable records across several pages.


ACS Information

This dialog box is accessed from the Information Editor. It allows you to enter Alternate Collating Sequence (ACS) information for a particular key specification. The following table includes a description of each of the controls.

ACS/Country Code	When selected, Btrieve uses the specified country ID and code page when sorting this key.
	County ID: A value of -1 is the system default.
	Code Page: A value of -1 is the system default.
ACS File	When selected, Btrieve uses the ACS defined in the specified file when sorting this key.
ACS File Name	The ACS file must be formatted according to the specification defined in the Programmer's Guide.
Browse Button	When selected, a Browse File dialog box is displayed. Use this dialog box to select a file name to be inserted in the ACS File Name control.
International Sorting Rule	This field allows you to specify a specific ISR table for sorting international data. Pervasive.SQL provides a set of pre-generated ISR tables for the following language and code page combinations:
	Language	Code Page	ISR Table ID
	English	437  MS-DOS Latin-US 850  MS-DOS Latin-1 1252  (MS-DOS Latin US)	PVSW_ENUS00437_0 PVSW_ENUS00850_0 PVSW_ENUS01252_0
	French	437  MS-DOS Latin US 850  MS-DOS Latin-1 1252  (MS-DOS Latin US)	PVSW_FRFR00437_0 PVSW_FRFR00850_0 PVSW_FRFR01252_0
	German	437  MS-DOS Latin US 850  MS-DOS Latin-1	PVSW_DEDE00437_0 PVSW_DEDE00850_0
	Greek	1253  (MS-DOS Latin US)	PVSW_GRGR01253_0
	Hungarian	852  MS-DOS Latin 2	PVSW_HUHU00852_0
	Japanese	932  Shift-JIS	PVSW_JPJP00932_1
	MS CompareString     Compatible English     Compatible French     Compatible Spanish         (traditional 1)     Compatible Hungarian	1252  (Windows Latin 1) 1252  (Windows Latin 1) 1252  (Windows Latin 1) 1252  (Windows Eastern            European)	MSFT_ENUS01252_0 MSFT_FRFR01252_0 MSFT_ESTR01252_0 MSFT_HUHU01252_0
	Spanish	437  MS-DOS Latin US    (Traditional:  pre 4-27-1994) 437  MS-DOS Latin US    (New post:  4-27-1994) 850  MS-DOS Latin-1    (Traditional:  pre 4-27-1994) 850  MS-DOS Latin-1    (New post:  4-27-1994) 1252 MS-DOS Latin US    (Traditional:  pre 4-27-1994) 1252  MS-DOS Latin US    (New post-4-27-1994)	PVSW_ESES00437_0 PVSW_ESES00437n0 PVSW_ESES00850_0 PVSW_ESES00850n0 PVSW_ESES1252_0 PVSW_ESES1252n0
OK Button	Click this button to close the dialog box and save any changes to the ACS Information.
Cancel Button	Click this button to close the dialog box without saving changes.


About Btrieve Maintenance Utility

The interactive Maintenance utility performs the following common file and data manipulations:

• 	Create new data files and description files based on file and key specifications you define.

•	View file and key specifications for existing data files.

•	Set and clear owner names for data files.

•	Recover changes made to a file between the time of the last backup and a system failure.

•	Create and drop indexes on data files.

•	Import and export ASCII sequential data.

•	Copy data between Btrieve data files.


Available Linked Keys

This specifies the number of unused 8-byte key place holders are available at the end of each record for supplemental linked-duplicatable keys. These place holders enable you to add new keys to a file that uses the linked-duplicatable method of storing duplicatable keys.


Balanced Indexing

Select the Balanced Indexing check box and the MicroKernel looks for available space in sibling index pages each time an index page becomes full. The MicroKernel then rotates values from the full page onto the pages with space available.


Blank Truncation

When you select this control, the MicroKernel performs the blank truncation method of compressing variable-length records.


Browse Dialog
Browse

This standard file browse dialog box lets you select the name of an existing file.

  Look in

  File List Area

  File Name

  Open Button

  Cancel Button


Cancel

Closes the dialog box without performing the operation.


Copy Data

This dialog box allows you to copy data from one MicroKernel-compatible file to another MicroKernel-compatible file. The following includes a description of each of the dialog box's controls.

From MicroKernel File	Specifies the name of the MicroKernel-compatible file to which the data is to be copied.
Browse Buttons	Specifies the name of the MicroKernel-compatible file to which the data is to be copied.
Browse Buttons	Displays a Browse File dialog box. The selected file name is placed in the corresponding file name edit control.
Execute Button	Click this button to close the dialog box and initiate the copy operation.
Cancel Button	Click this button to close the dialog box without copying the data.


Create File

This option lets you create a new MicroKernel or description file using the file and key information currently in the File Information Editor.

File Type

  MicroKernel Compatible File

  Description File

  Index Only


Create Index Dialog
Create Index

This dialog box allows you to create Btrieve indexes. The type of index you can create depends on the current state of the MicroKernel-compatible file’s log key.

If the log key is the system-defined key and the system-defined key is present, you cannot create a system-defined key. If the log key is the system-defined key and it has been dropped, you can create the system-defined key. In this case, ‘SYSKEY’ appears in the Key Number to Use for Create list and you do not have to specify a Key Specification Number from the File Information Editor.

If the log key is one of the user-defined keys or the file does not have system data, ‘SYSKEY’ does not appear in any of the key number lists.

The following table includes a description of each of the dialog’s controls:

Index Type	This operation allows you to create either an internal or external index. The Internal Index option creates a new index within the specified MicroKernel-compatible file. The External Index option creates an external index file based on the specified MicroKernel-compatible file. To create an internal index, you must specify an existing MicroKernel Data File, a Key Specification Number from the Information Editor, and the Key Number you want the new index to have in the MicroKernel-compatible file.  To create an external index, you must specify an existing MicroKernel Data File, the name of the external index file to be created, and a Key Specification Number from the Information Editor.
Data File	Specifies the name of the existing MicroKernel-compatible file to which you want to add indexes.
External Index File	Specifies the name of the external index file to create if you select the Create External Index File option.
Key Specification Number in Information Editor to Use	This list contains all key numbers currently specified in the Key Selection Controls of the Information Editor. The selected key specification number is used when creating either an internal or an external index.
Goto Editor Button	Click this button to display the File Information Editor. Click this button to quickly switch to the Information Editor so that you can create the desired key specification. Then switch back to the Create Index and perform the create index operation
Existing Key	This list contains all existing key numbers in the specified MicroKernel file. This is for information only. You do not need to select a key from this list. If the file has a system-defined key and the system-defined key is present, ‘SYSKEY’ appears in this list.
Key Number to Use for Create	Lists the key numbers available (not defined for the MicroKernel-compatible file). Highlight the key number you want to use when creating the index. If the file has a system-defined key and the system-defined key is dropped, `SYSKEY' will appear in this list.
Refresh/Execute	Once the user has specified the name of an existing MicroKernel-compatible file, this button updates the Btrieve Existing Keys and Key Number to Use lists. You can then select the execute option to create the index. The execute option will not be enabled unless you first specify all necessary information for the desired operation.
Cancel/Close Button	Click this button to close the dialog box. After you have created an index, the Cancel button changes to Close, signifying that you cannot undo any completed operations.


Create Stat Report

This option displays a file browse dialog which allows you to specify the name of the report file to create. You can also choose to view the report file after it has been created. Below is a description of each of the dialog box's controls.

  Data File

  Report File

  View Report

  OK Button

  Cancel Button


Data Compression

When you select the Data Compression check box, Btrieve compresses the file’s records before inserting or updating them and then uncompresses them when it retrieves the records.


Data File

Specifies the name of the MicroKernel-compatible file for which you want to create a report.


Data Processing

This dialog box displays the status of the data manipulation process. For more information on any status messages, please refer to Status Codes and Messages.


Description File

Select this option to create a description file.


Description File Comments

This dialog box is accessed from the File Information Editor. It allows you to enter, edit, or view description file comments.

Description Edit Control	This multiple line edit control is where you enter the comment you want to save in the description file.
OK Button	Click this button to close the dialog box and save your changes.
Cancel Button	Click this button to close the dialog box without saving changes.


Drop Index

This dialog box allows you to drop existing internal indexes in a MicroKernel-compatible file. If the log key is the system-defined key and the system-defined key is present, you can drop the system-defined key. In this case, ‘SYSKEY’ appears in the Existing Key list.

If the file’s system-defined key has already been dropped or the file does not have system data, you cannot drop the system-defined key. In this case, ‘SYSKEY’ does not appear in the Existing Key list.

The following table includes a description of each of the dialog box’s controls:

MicroKernel File	Specifies the name of the existing MicroKernel-compatible file for which you want to drop indexes.
Existing Key	Lists the key number defined for the file. Highlight the number of the key whose index you want to drop. If the log key is the system-defined key and the system-defined key is present, ‘SYSKEY’ appears in this list. If the file’s system-defined key has already been dropped or the file does not have system data, ‘SYSKEY’ does not appear in this list.
Renumber Keys	When dropping an index, you can instruct the MicroKernel to maintain the current numbers of any remaining keys. If you select the Renumber Keys check box, the MicroKernel decrements by 1 the number of any remaining keys with a value greater than the dropped index. For example, if you have three keys numbered 2, 3, and 5, and you delete key number 3, the following occurs: if you do not renumber, the remaining keys are numbered 2 and 5. If you renumber, the remaining keys are numbered 2 and 4.
Refresh/Execute Button	You can click the Refresh List button to update the information in the Drop Index dialog box based on the changes you may have made in the File Information Editor dialog. The Execute option is not enabled unless you first specify all necessary information.
Cancel/Close Button	Click the Cancel button to exit the dialog box. After you have dropped an index, the Cancel changes to Close, signifying that you cannot undo any completed operations.

Refer to Miscellaneous File Information Help for more information about the other controls in this dialog box.


File Information
File Specification Controls Help

The following table provides a description of each control used to define the file specification of a MicroKernel file. These controls correspond to the various file attributes Btrieve supports when creating a MicroKernel-compatible file. For more information about these controls, refer to the Advanced Operations Guide  or the Programmer’s Guide

  Record Length

  Page Size

  # Keys

  # Segments

  Available Linked Keys

  Key-Only

  Balanced Indexing

  Pre-allocation

  # Pages

  Data Compression

  Variable Records

  Blank Truncation

  Include VATs

  % Free Space


File Information Editor

The File Information Editor Window allows you to easily enter, edit, and view MicroKernel file and key information.  Once complete, the information can be used to create MicroKernel-compatible files, indexes, and description files. The information in the window is grouped into three sets of controls.

File Specification	Specify the record length, page size, number of keys, segments, and other attributes of the data file.
Key Specification	Specify attributes of a MicroKernel-compatible file related to a specific key or a segment within a key.
Miscellaneous File Information	Specify information about the MicroKernel or description file not part of the file or key specifications.
Much of the information in the editor is interrelated. These relationships are often indicated by enabling or disabling controls. This approach not only helps you understand the relationships between the various MicroKernel file and key attributes; it also helps to prevent you from entering inconsistent information.

Here are a few examples:

All key and segment controls (except the create key button) are disabled if a key or key segment is not selected.

The Blank Truncation control is disabled unless the Variable Records control is checked.

The ACS information button is disabled unless the current segment's Use ACS control is checked.

Related Topics

Description File Comments

ACS Information

Create File


File List Area

Displays the files in the current directory.


File Name

Specifies the selected file name.


Getting Help

For context-sensitive help at any time while your are running the Btrieve Maintenance utility, you can use one of the two methods:

Help Menu	Select the Help option from the menu bar at the top of the Maintenance utility window.
Help Button	Each dialog box in the Maintenance utility has a Help button that displays help about the specific dialog box.


Help on Help

For information about using the Windows help system, select Help | Using MS Help from the Maintenance utility window.


Include VATs

When you select this control, the MicroKernel includes Variable-tail Allocation Tables (VATs) in the file. VATs are used by the MicroKernel to accelerate random access to the variable-length portions of records, but also to limit the size of the compression buffer used during data compression.


Index Only

Select this option to create a description file with the specification for the currently specified index (in the Information Editor). This is a convenient way to save individual index specifications.


Key - Segment Groupbox Help Panel
Key - Segment Group box Help

The controls in this group box specify information about a particular segment of the current key.

Data Type	This control specifies the Btrieve data type for the key. The data type determines how Btrieve sorts the bytes specified for this key segment.
Position	This control specifies the starting offset (1 relative) of the current key segment.
Length	This control specifies the length of the key segment field.
Null Value (Hex)	This control specifies the null value Btrieve uses when determining whether a key value should be treated as null. This control is enabled only if the Null Key control was checked for this key.
Case Insensitive	When this control is checked, Btrieve sorts this segment without regarding case. For example, the characters a and A are given the same ordinal values. This control is only enabled if the data type of the segment is string, zstring, or lstring.
Descending	When you select this control, Btrieve collates the key segment in descending sort order.
Use ACS	When you select this control, Btrieve expects an ACS to be specified for this segment. Use the ACS Information specify the ACS for this key. All segments of a particular key do not need to use an ACS. However, all that do use an ACS must use the same one.


Key Groupbox Help Panel
Key Group box Help

The controls in this group box specify information common to ALL segments of the current key.

Duplicates	Select the Duplicates check box to permit Btrieve to allow more than one record in the file to contain the same value for this key field.
Modifiable	Select the Modifiable check box to permit Btrieve to allow a key value for this key field to be updated.
Repeating Duplicates	Btrieve supports two methods of storing duplicate values for a key: repeating duplicates and linked duplicates. Select the Repeating Duplicates check box so Btrieve uses the repeating duplicates method.
Null Key	Selecting the Null Key check box specifies whether the key has a null value. You can use a null value in a key when the data for the key is unavailable or when you do not want the MicroKernel to include a record for that key in the index. Btrieve supports two methods for determining whether a particular key value is a null value: Any Segment and All Segments. These methods differ only for multi-segment keys.
Any Segment	When you select this option, Btrieve treats a key value as null if ANY segment of the key contains a null value.
All Segments	When you select this option, Btrieve treats a key value as null only if ALL segments of the key contain a null value.
ACS Information	This button displays the ACS Information. This dialog box lets you specify an alternate collating sequence used in sorting the current key. Any segment of this key which uses an ACS will use the ACS specified here. This button is only enabled if the Use ACS control in the Segment Group Box is checked.
Unique Values	This is a read-only control specifying the number of unique key values contained by this key in a recently-opened MicroKernel-compatible file. N/A is displayed if the current editor information was not loaded from an existing MicroKernel-compatible file.


Key Lists Help Panel
Key Lists Help

These lists and associated buttons enable you to add or delete key specifications from File Information Editor as well as change the current specification being displayed.

Key Selection List	This list contains all key numbers currently defined in the Information Editor. As you scroll through this list, the key information corresponding to the key number is displayed in the editor. The three buttons below the control allow you to manipulate the key numbers.
Insert Key Button	Click this button to insert a new key number after the one currently selected. If there is already a key at this position, that key (and all subsequent consecutive keys) are incremented by one.
Delete Key Button	Click this button to delete the currently selected key. Subsequent keys are not renumbered. This button is shown only when a key is currently selected in the key selection list.
Compress Key Button	Click this button to renumber all key numbers in the list consecutively starting with 0 (zero). This button is shown only when there are holes in the list of key numbers.
Key Segment Selection	This list contains all key segment numbers defined for the currently selected key. As you scroll through this list, the key segment information corresponding to the segment number is displayed in the editor. The two buttons below this control enable you to manipulate the key segment numbers in the list.
Insert Segment Button	Click this button to insert a new key segment number after the one currently selected. If there is a segment at this position, that segment (and all subsequent segments) is incremented by one.
Delete Segment Button	Click this button to delete the currently selected segment. If this is the last segment for the current key, the entire key is deleted. Subsequent keys are renumbered. This button is displayed only when a segment is currently selected in the key segment selection list.


Key Specification Controls Help Panel
Key Specification Controls Help

The controls used to specify key attributes supported by Btrieve are located at the bottom of the File Information Editor. The controls have been divided into three groups: For more information about these controls refer to the Advanced Operations Guide.

Key Selection Lists	These lists are located at the center of the key specification area. They enable you to add or delete key specifications from the Information Editor as well as change the current specification begin viewed.
Key Information Group Box	This group box is to the left of the key specification area. Its controls specify information common to ALL segments of the current key.
Key-Segment Group Box	This group box is to the right of the key specification area. Its controls specify information about a particular segment of the current key.
Related Topics

Key Group box Help

Key Lists Help

Key - Segment Group box Help


Key-Only

Select the Key-Only check box and the MicroKernel creates a key-only file. This type of file contains no data and includes only one key.


Load Data

This dialog box allows you to load data from an unformatted sequential file to a MicroKernel-compatible file. The following table includes a description of the controls.

From Sequential File	Specifies the name of the unformatted sequential file from which the data is to be copied.
To MicroKernel File	Specifies the name of the MicroKernel-compatible file to which data is copied.
Browse Buttons	Displays a Browse File. The selected file name is placed in the corresponding file name edit control.
Execute Button	Click this button to close the dialog box and initiate the load operation.
Cancel Button	Click this button to close the dialog box without performing the load operation.


Look in

Displays a list of directories from which you can choose a file.


MicroKernel Compatible File

Select this option to create a MicroKernel-compatible file.


Miscellaneous File Information Help

The following table includes a description for each miscellaneous control. For more information about these controls, refer to the Advanced Operation's Guide.

Load Information . . .	This button displays a file selection dialog box that allows you to load Btrieve information into the editor from either a MicroKernel-compatible file or a description file.
Create File . . .	This button displays a file selection dialog box which allows you to save the current editor information to either a MicroKernel-compatible file or a description file.
Help	Click this button to display context-sensitive help for the Information Editor.
Set to Defaults	This button resets all of the controls to their default values. If you have made changes, you are prompted to create a file with the current information before continuing.
Description Comments . . .	This button displays the Description Comments which you can use to edit comments stored in description files.
Owner Name	You can enter up to eight characters in this edit control. After creating a new MicroKernel-compatible file using the current information in the editor, the Btrieve Maintenance utility sets the owner of the file to this value.
Version	If the last file opened or created was a MicroKernel-compatible file, this read-only control displays the file’s version. The version does not always indicate the version of the MicroKernel used to create the file. Rather, it indicates the earliest version of the MicroKernel which supports all the attributes of this file, including any format changes. For example, a file created by MicroKernel version 6.15 with no version 6.15 attributes will have a file version of 6.0. As a second example, a version 6.x formatted file can never have a version less than 6.0. If the last file accessed was not a MicroKernel-compatible file, N/A is displayed.
Total Records	If the last file opened or created was a MicroKernel-compatible file, this read-only control displays the number of records in the file. If the last file accessed was not a MicroKernel-compatible file, N/A is displayed.
Show 6.x Info	This button is only displayed after a pre-version 6.x file has been loaded or created. In this case, all controls specific to version 6.0 and above are hidden. If you click this button, all of the controls will be displayed again.


OK Report
OK

Click this button to create the report file.


Open

Opens the specified file.


Owner Name

This dialog box is displayed when the Btrieve Maintenance utility attempts to open a MicroKernel-compatible file which has an owner name. You should specify the file's owner name and press Enter. If the owner name is valid, the operation will continue. If it is not valid, this dialog box is displayed again. Press Cancel to halt the operation.


Page Size

This control specifies the page size Btrieve uses when creating a file.


Pre-allocation

The MicroKernel typically creates a new file with the minimum number of pages needed to support the various file and key attributes specified. When you select the Pre-allocation check box, you may specify up to 65,535 pages in the # Pages control. After loading the file information from an existing MicroKernel-compatible file, this control specifies the number of unused pages remaining in the file.


Record Length

This control specifies the logical length of the fixed portion of the data record.


Report File

Specifies the name of the report to create.


Roll Forward

This dialog box enables you to specify a specific file, list of files, volume or directory you want to roll forward. You can also generate an output file of logged operations, called a dump file. The following table provides a description of each control.

Operation Type	You can select either a single file, list of files, volume name or drive letter to roll forward. When you select either volume name or drive letter, you must insert a back slash (\) or forward slash (/) at the end. (For example, for volume name you would enter something similar to \\server\vol1\, and for drive letter you would enter something similar to D:\.)
Browse	This is only enabled if you select single file or list of files. If enabled, the Browse is displayed. From this dialog box, choose the specific file or list of files to roll forward.
Dump File Options	A dump file is a listing of all Btrieve operations required to perform the roll forward tasks. By default, a dump file is not created.
Generate Dump File	Select the Generate Dump File check box to create a dump file. Additionally, when you select this option, the other Dump File controls are enabled.
Only Create Dump File	Select the Only Create Dump File check box if you do not want to perform a roll forward operation but want to generate the dump file.
Dump File Name	The edit line contains the name of the Dump File, which must begin with a slash and NOT contain a drive letter or server/volume name.
Data Buffer	This displays the number of data buffer bytes to write to the dump file for each Btrieve operation.
Key Buffer	This displays the number of key buffer bytes for each Btrieve operation.
Display Numbers as HEX	Select the Display Numbers as HEX check box to format the numbers in the dump file output as hexadecimal. If you do not select this check box, the numbers are displayed in ASCII format.
Verbose	Select the Verbose check box to include additional information such as user name, network address and time stamp in the dump file.
Execute Button	Click this button to validate the data you specified and generate the dump file if you selected that option. If the data is valid, the Roll Forward Stat is displayed.
Cancel Button	Click this button to close the dialog box without generating a dump file or performing roll forward operations.


Roll Forward Stat

This dialog box is displayed when you execute roll forward changes. As files are processed, they are added to the scrolling list box. Each entry displays the Btrieve status code that is returned from the roll forward operation as well as the file name of the file processed.


Save Data

This dialog box lets you save data from a MicroKernel-compatible file to an unformatted sequential file. The following table includes a description of the controls.

From MicroKernel File	Specifies the name of the existing MicroKernel-compatible file you want to save.
To Sequential File	Specifies the name of the sequential file to create.
Use An Index	When you select the Use An Index check box, the Btrieve Maintenance Utility saves the data sorted by either an internal index or an external index file. By default, the Maintenance utility does not use an index, meaning that records are exported according to their physical position in the data file.
Internal Index #	When you select this option, a list of all keys currently defined in the specified MicroKernel-compatible file is displayed. Use the Refresh button to update this list if you change the name of the MicroKernel-compatible file. Select the key number to use when saving the records from this list.
External Index File	When you select this option, an edit control for specifying the name of the existing external index file is displayed.
Cancel	Closes the dialog box without saving the data.


Set - Clear Owner

This dialog box enables you to set or clear an owner name from an existing MicroKernel-compatible file. The following table provides a description of each control.

MicroKernel File Name	Specifies the name of the MicroKernel-compatible file for which to set or clear the owner name.
Clear Owner	Select this option to clear an owner name from the MicroKernel-compatible file.
Current Owner	Used with the Clear Owner operation to specify the current owner name in the MicroKernel-compatible file.
Set Owner	Select this option to set a new owner name for the MicroKernel-compatible file.
New Owner	Used with the Set Owner operation to specify the new owner name for the MicroKernel-compatible file.
Permit read-only access without an owner name	When you select this check box for the Set Owner operation, Btrieve allows you to access the file in read-only mode without specifying the owner name.
Encrypt Data in file	When you select this check box for the Set Owner operation, Btrieve encrypts all data in the file.
Cancel/Close	After you have set or cleared an owner name, the Cancel button changes to Close which signifies that you cannot undo any completed operations.


Variable Records

When you select the Variable Records check box, Btrieve creates a file which allows variable records (records longer than the fixed length).


View Report

Select the View Report check box to display the report file in a window after it has been created.


View Stat Report

If you select the View Report option in the Create Stat Report dialog box ,this dialog box is displayed after the report is created. This dialog box displays defined characteristics of a data file and statistics about the file’s contents.