Re: [Patch] ALTER SYSTEM READ ONLY

Hi All,

Attaching a new set of patches rebased atop the latest master head and includes
the following changes:

1. Enabling ALTER SYSTEM READ { ONLY | WRITE } support for the single-user,
discussed here [1]

2. Now skipping the startup checkpoint if the system is read-only mode, as
discussed [2].

3. While changing the system state to READ-WRITE, a new checkpoint request will
be made.

All these changes are part of the v2-0004 patch and the rest of the patches will
be the same as the v1.

Regards,
Amul

1] https://postgr.es/m/CAAJ_b96WPPt-=vyjpPUy8pG0vAvLgpjLukCZONUkvdR1_exrKA@mail.gmail.com
2] https://postgr.es/m/CAAJ_b95hddJrgciCfri2NkTLdEUSz6zdMSjoDuWPFPBFvJy+Kg@mail.gmail.com