Adobe DC Pro is not searchable with large PDF files (about 700mb).
As mentioned above, Acrobat Pro DC is not searchable with large PDF files. Does it mean that you are looking for a word and the search result isn't coming up only with the large file? Or is it something else?
Would you mind elaborating a bit more about the situation?
Meanwhile, would you mind sharing the Adobe Acrobat version you are using? To check the version, go to Help > about Acrobat and ensure you have the recent version 22.001.20169 installed. Go to Help > Check for updates and reboot the computer once (you must save all the work before restarting)
Also, navigate to Acrobat>Edit>Preferences> Search> Purge Cache Contents>OK
When the source of a PDF was an image instead of a typed document, the PDF file does not contain searchable text by default. If the source image had a quality of at least 72 dpi, you can use Adobe Acrobat to transform the PDF using the built-in Optical Character Recognition (OCR) feature.