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This method extracts the "physical descriptions" array from the instance record; records that do not have a physical descriptions array will NOT drop out, because the "left join lateral" function used in this query will keep all instance records in the results set, including those that do not have array values for physical descriptions. ***Note that it is generally best to AVOID using the marc__t table in queries, whenever possible, because of the ongoing problems with data accuracy (still true as of 3-23-26).*** 

As stated above, because the physical description field of the instance record is a text-entry field that has no enforced data entry format, the parsing statement will not yield highly accurate results. It works in cases where a page count number is followed by "p." or "pages" or "leaves" or "l." and when the first number in the description field (reading from left to right) is the actual number of pages or leaves, and not some other value. 

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