The MSVC linker provides a feature known as "fast PDBs" or "mini PDBs". It is enabled using the /DEBUG:FASTLINK linker option. This option generates PDBs that contain only minimal debug information, some of which consists of pointers to debug information in other files.

Mini PDBs were intended to reduce developer inner loop times by shortening linking times. However, recent improvements in linker performance have reduced the performance gap between full PDBs and mini PDBs. /DEBUG:FASTLINK is now considered a deprecated feature.

A mini PDB file can be identified by the presence of the MinimalDebugInfo feature code in the PDB Information Stream.

The MinimalDebugInfo feature code determines the value of the num_buckets parameter in the GSI and PSI Name Tables. It is therefore required in order to decode those tables. If the MinimalDebugInfo feature is absent, then the value of num_buckets is 0x1000. If the MinimalDebugInfo feature is present, then the value of num_buckets is 0x3ffff.

References

• /DEBUG (Generate debug info)