Portsmouth manager Kenny Jackett admitted he was disappointed after his side’s second successive goalless draw.
The 0-0 draw at Rochdale followed last weekend’s stalemate at home to Shrewsbury.
Dale had the better of the first half, with Ollie Rathbone and Alex Newby both going close.
But Portsmouth applied most of the pressure after the interval, with John Marquis having several chances to score as Rochdale goalkeeper Gavin Bazunu, on loan from Manchester City, pulled off some good saves.
Jackett said: “There’s some frustration.
“We built up a good head of steam in the second half and got on top, but couldn’t quite get the finish that we needed to some very good balls in the box.
“We settled down and looked strong. Rochdale always do pose a threat and will leave people up front to try to nick it.
“But we are frustrated with the way the game went. I did feel there was a goal or goals there for us today and unfortunately we couldn’t get any.
“Nil-nil at half-time isn’t necessarily a bad scoreline. It was 50-50 in the first half. We needed to be better and confident on the ball and we were. We talked at half-time about relaxing a bit.
“We did have good control. I was pleased with the chances we created but unfortunately we couldn’t get over the line with the win we wanted.”
Rochdale went into the game on back of the 3-1 opening-day defeat at Swindon and boss Brian Barry-Murphy was pleased with his side’s efforts.
“It felt on the sidelines that it was thrilling draw and it’s hard to believe it was 0-0,” he said.
“I thought we were pretty good in the first half in the way we took them on. It’s testimony to the efforts the lads are putting in.
“We felt as if we had a clear advantage in the first half and we should have scored goals, but we didn’t.
“We were on the front foot and had numerous chances – I felt we could and should have scored.
“As such, it was inevitable they were going to have chances in the second half and we managed to hold out.
“I’m excited for the players that we got a result in the end because I thought that we deserved it. No one gave us a chance against Portsmouth.”
Dale lost new signing Stephen Humphrys and captain Eoghan O’Connell through injury during the game.
Barry-Murphy added: “I suppose the only negative is that those efforts can come at a cost and we saw that with the players we lost to injury today.”