I research the Irish Family History Foundation's database. It contains 12,800,000 surviving rcds for abt 70% of Irish counties. Rcds are increasingly sparse B4 1840, rare B4 1800. Cos. Donegal and Derry were recently added to the database.
Note 1 - Without a KNOWN county, the chance of an ancestor's rcds NOT being in this database is AT LEAST 30%.
Note 2 - Only 1/2 of Co. Cork's rcds are in this database.
Note 3 - The RC church kept control over most parish rcds from Tipperary (north). These are ONLY available thru the Tipperary Family History Research center at a substantial fee (regardless of outcome).
For David Connell B 1888 (exact), Co. Cavan, with the father's forename unknown, I found 1 rcd in Killann RC parish. Note - Baileboro is the name of a Church of Ireland and Methodist parish - Not RC. The father's forename for this event wasn't rcd'd.
For David Connell M 1912 +/- 4 yrs, somewhere in Ireland, I found 9 rcds: 1910 Donegal, 1910 Derry, 1910 Cork, 2-1911 Antrim, 2-1911 Tyrone, and 1916 Derry.
For Joha(nna) Cavanaugh M ditto, I found 0 rcds.
Few church B/M/D rcds were kept after 1900. Civil rcds were mostly destroyed in the Four Courts fire in 1922. Contact the General Register Office at http://www.groireland.iehttp://www.groireland.ie for those civil records which survived.
Google the Foundation's name to lead you to this database. Register, opt to be notified as rcds are added and browse. Pls post your search results to my genforum msg.