我正在尝试通过使用 OPL 将其编写为线性程序并使用 CPLEX Studio 解决它来解决网络流问题。CPLEX Studio 用了 26 分钟解决了这个问题。但是，该Engine Log说Network time = 0.21 sec：
CPXPARAM_LPMethod 3
Tried aggregator 1 time.
LP Presolve eliminated 914361 rows and 916674 columns.
Aggregator did 5 substitutions.
Reduced LP has 4629 rows, 457853 columns, and 913392 nonzeros.
Presolve time = 1.28 sec. (955.67 ticks)
Extracted network with 4630 nodes and 457853 arcs.
Extraction time = 0.04 sec. (22.54 ticks)
Iteration log . . .
Iteration: 0 Infeasibility = 3444.000000 (-1.21856e+06)
...
Iteration: 50000 Objective = -1158876.510000
Network - Optimal: Objective = -1.1643204900e+06
Network time = 0.21 sec. (53.14 ticks) Iterations = 54799 (15500)
我不完全确定我是否正确阅读了日志。
这是否意味着预求解（或其他开销）需要 26 分钟来消除行/列等，而实际的网络求解只需要 0.2 秒？
如果是这样，绕过presolve会更快吗？（如果有必要，我怎样才能绕过预解析？）