How does tabix work?

Question

[captainlabman]

My question is why do you need Tabix at all? For example, when annotating VCF files with tab delimited files. Does it speed up annotation? If so, how does the presence of intervals (tabix) speed up the reading of lines from the source tab delimited files? I didn't find the answer on Google.

Answer 1

[Pierre Lindenbaum]

My question is why do you need Tabix at all? I didn't find the answer on Google.

https://pubmed.ncbi.nlm.nih.gov/21208982/

Tabix: fast retrieval of sequence features from generic TAB-delimited files

Tabix is the first generic tool that indexes position sorted files in TAB-delimited formats such as GFF, BED, PSL, SAM and SQL export, and quickly retrieves features overlapping specified regions. Tabix features include few seek function calls per query, data compression with gzip compatibility and direct FTP/HTTP access. (...) It is particularly useful for manually examining local genomic features on the command line and enables genome viewers to support huge data files and remote custom tracks over networks.