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SAS Metadata Model Conventions

Storage of Date, Time, and DateTime Values

Date, time, and datetime information are stored on the metadata server as GMT values in SAS date, time, and datetime encoding. These values are then formatted in the XML according to a specified locale. The metadata server supports a US-English locale. You can use a different locale in the client by setting the OMI_NOFORMAT flag in a GetMetadata request. For information about the GetMetadata method, see the SAS Open Metadata Interface: Reference and Usage.

The OMI_NOFORMAT flag gets date, time, and datetime data as raw floating point values that the client can use as SAS date, time, and datetime values and format however they want. Because objects are persisted to disk with a GMT datetime value, an object created in local time might have a different datetime value on disk. For example, an object created at '30May2003:16:20:01' CST could have a persisted datetime value of '30May2003:21:20:01'. To accommodate the storage conversion, the server converts values that you specify in an XMLSELECT search string to GMT for you. However, the datetime values returned by the server will look different than the values that you submitted in the search string.

"V" in Length Attribute

Attributes that have no practical length limitation are represented with a "V" in the Length attribute, for example, "V64". The "V" indicates the property is variable length (arbitrarily large). The documented length (64) is the maximum length of the string that can be stored before an overflow algorithm is invoked. Storing a string that exceeds the documented length causes one or more TextPage objects and corresponding associations that connect them to the original object to be created to store the string. Each TextPage object holds an additional 1,000 characters of text.

Use of the overflow algorithm has performance overhead associated with it. XMLSELECT processing also will not search overflow text in attempts to qualify an object for selection.

For metadata types that do have a length limit, the SAS Open Metadata Interface truncates any values that exceed the documented length.

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